Wikipedia talk:Manual of Style/Dates and numbers/Archive 155

MOS:TV "overhaul" planned
Below is a copy of a notice, and my response to it, posted at WP:Village pump (policy). I think this should involve considerable input from MoS watchers in general, or all kinds of unintended effects could result, most likely WP:LOCALCONSENSUS-based forking of advice – on things like date formatting, WP:CRYSTAL treatment of future episodes/seasons, in-universe writing, etc. – from various sections in the main MoS, its subpages, and other guidelines. I doubt there would be any to do that, but we've seen it happen repeatedly before with regard to comics and several other media.

— SMcCandlish ☺ ☏ ¢ ≽ʌⱷ҅ᴥⱷʌ≼  04:34, 30 June 2016 (UTC)


 * I don't think "headed up by myself" is such a good sign either.  E Eng  09:01, 30 June 2016 (UTC)
 * I believe my concerns about it were and are valid. They're basically stating outright that they're drafting it in a wikiproject rathole amongst their localconsensus, with the intent to advance a proposal, fully-formed, at the guideline talk page later. I think that's ass-backwards.  The proposal development discussion should have been taking place at WT:MOSTV.  I guess the horse is out of the barn at this point, but at least we're pointing in the direction it ran off so it can be rounded up.  Stuff like this makes me more and more convinced that wikiprojects needs to be re-thought.  They often cause more problems than they're worth (though I've started many of them).  Something more verbish than nouny, that does not encourage a sense of "membership" in a private club that claims "scope" over topics.  "Wiki-collaborating", perhaps.  — SMcCandlish ☺ ☏ ¢ ≽ʌⱷ҅ᴥⱷʌ≼  08:39, 21 July 2016 (UTC)

Ranges other than dates
Specialized MOS pages, such as this one, normally elaborate on guidelines stated in the main MOS. However, MOSNUM discusses omission of common (i.e., like) digits in the last number of a range only for dates. The main MOS gives an example of this principle for page numbers, but does not mention the general principle. In my opinion, we should add a section to MOSNUM on ranges generally, including the use digit omission, with examples and exceptions other than dates, and cross-reference the subsection on date ranges. The main MOS should also mention the general principle and hyperlink to the new MOSNUM.—Finell 23:31, 3 July 2016 (UTC)
 * Yes, MOSNUM has "advice-forked" a bit too much over the last couple of years, without being synched with the main MoS page.  — SMcCandlish ☺ ☏ ¢ ≽ʌⱷ҅ᴥⱷʌ≼  08:41, 21 July 2016 (UTC)

Date range when first year is circa and second year is not...
I couldn't find a simple example, but today's TFP has a date range displayed as "c. 1618–1620", should that be "c. 1618 – 1620" (the 1620 appears to be known, while the 1618 is approximate)? The Rambling Man (talk) 16:35, 1 August 2016 (UTC)
 * I've added something on this though be sure to see the edit summary.  E  Eng  19:32, 1 August 2016 (UTC) You used a comma splice, shame on you!

Death date known, birth unknown
I'm pretty sure that "(?-1733)" is wrong and "(died 1733)" is right (eg in Daniel Delander) but can't find this explicitly stated anywhere to quote on the editor's talk page.

Is there something written about how to present the death date where the birth date isn't known, in which case please give me a link to it. If it isn't already written could I suggest that it would be a useful addition to this page, perhaps immediately following the rule For a person still living: Serena Williams (born September 26, 1981) is a ..., not (September 26, 1981 – ) or (born on September 26, 1981)., or alternatively in WP:APPROXDATE. Thanks. Pam D  23:03, 22 June 2016 (UTC)
 * Interesting, this definitely used to be in the MoS as "(died 1733)" (here's a random 2007 version of the page that has it), but I'm not sure when or why it was removed. Possibly it was inadvertently lost at some point? So barring some discovery of a discussion to remove it, I think it's safe to re-add it. —  Crumpled Fire   • contribs • 23:12, 22 June 2016 (UTC)


 * I note that Manual of Style/Biographies refers to this page for how to write birth and death dates. So if we add it back, I don't think we need to worry about conflicting with another part of the MOS.
 * Here's the diff where the text was overhauled on 11 July 2008. I did not look to see if those changes were later reverted and reintroduced, but in checking the history once every year or so, I found the text to be relatively stable after that July 2008 change. Any discussion should have happened around Wikipedia talk:Manual of Style (dates and numbers)/Archive 105 or thereabouts. I did not find any such discussion, which does not mean that it didn't happen. – Jonesey95 (talk) 05:17, 22 July 2016 (UTC)


 * Try this: . (I think it's more akin to "person still living" than to "incomplete date".) If anyone can think of a real example, please substitute it.  E Eng  05:39, 22 July 2016 (UTC)

Date ranges for music-related articles
Which date range format should be used in music-related articles – 1965–73 or 1965–1973? I encountered both formats in several (GA and even FA) music-related articles and now I'm confused, because it looks like people use whatever format they want. Any thoughts? – Sabbatino (talk) 09:00, 20 July 2016 (UTC)


 * I can't imagine a reason for music to have a different format from other articles. In topics such as certain sports (e.g. basketball) where the season begins in one calendar and continues into the next, it might make sense to have a special convention about how to write the name of seasons, but I don't see how that would apply to music. Jc3s5h (talk) 11:32, 20 July 2016 (UTC)


 * If those articles pass the FA/GA review then there must be some reason why XXXX–YY or XXXX–YYYY were used for different articles. – Sabbatino (talk) 11:43, 20 July 2016 (UTC)
 * That's mistaking correlation for causation. If you actually participate in or just observe FAC (and GAN), you'll see that they mostly DGaF about MoS compliance. It's listed as one of the criteria, but it is not "enforced" any further than someone unmistakably raising an MoS-related objection (and even if they do, if the WP:VESTED WP:OWNers of the article in question scream and holler enough, often the article will be promoted over the MoS-related objections anyway).   Nine times out of ten, any divergence from MoS in a GA or FA candidate is because someone working on the article has a pet peeve against some line-item in MoS and is actively defying it, gambling that other editors want to promote an otherwise good/featured-class article more than they want to fight about a style quibble.  So, don't read into it.  Also be aware that a large number of GAs/FAs have style flaws in them that were present when they passed an initial review that took place  the applicable MoS line-item existed in its current form, or due to other, later editors making it non-conformant long after the GAN/FAC.  The "my article doesn't have to comply with MoS on this point, because these other FAs don't comply with it" angle is a cockamamie WP:OTHERCRAPEXISTS and special pleading fallacy.  In both cases, it should simply be normalized to what MoS now advises. A GA or FA icon is not some magical "exemption from guidelines henceforth" license, nor does it affect in any way other editors' rights to edit that article just like an other page on the system.  All a GA or FA badge indicates is that some subset of other editors agree that the article  with the core content policies, was well-written, and passed a few other criteria (different lists for GA and FA) to the extent that reviewers at the time cared to push for them to be complied with. Per common sense, we also tend to edit such articles more carefully and with more discussion, on average, than some random stub or B-class article, because it's at least been through some level of vetting beyond the regulars at the article in question.  — SMcCandlish ☺ ☏ ¢ ≽ʌⱷ҅ᴥⱷʌ≼  08:54, 21 July 2016 (UTC)
 * Saying "There must be an underlying cause to why some cows have spots and others do not" has nothing to do with correlation vs. causation.
 * GA calls for compliance with only a very few bits of MOS.
 *  E Eng  13:54, 21 July 2016 (UTC)
 * Not comparable; a comparable statement would be "If all this beef passed FDA approval, then there must be some reason why some farmers sent spotted cows and some sent all-black ones". The conditional and the proposition are not related in any way except accidentally. The "if ... then ... must" construction in there (both the example and the original statement about FA) is clearly fallacious, since it directly states a causative relationship.
 * That's what I already said: 'they mostly DGaF about MoS compliance. It's listed as one of the criteria, but it is not "enforced" any further than someone unmistakably raising an MoS-related objection' ... 'passed a few other criteria (different lists for GA and FA) to the extent that reviewers at the time cared to push for them to be complied with'.
 * — SMcCandlish ☺ ☏ ¢ ≽ʌⱷ҅ᴥⱷʌ≼  20:15, 21 July 2016 (UTC)
 * Oh, SM, sometimes you get so wrapped up. There's no conditional here, since the if here isn't a conditional -- it's a colloquial way of stating the fact situation i.e. here it means Given that we find. To (potentially) confuse correlation with causation, you first need to have a correlation i.e. A tends to be seen with X, ~A tends to be see with ~X. There's none of that here. He's just saying that he can't see why some "approved" articles use one format, while others use another, and assumes there must be some hidden reason for the difference. That last assumption might be false (I think it is) but it's not mistaking correlation for causation.
 * FA lists MOS compliance as a requirement. GA calls out just 3 or 4 bits of GA as a requirement.
 *  E Eng  20:33, 21 July 2016 (UTC)

Doesn't the fact that MOS recently was changed from XXXX-YY to XXXX-YYYY have something to do with this? New GA articles have the new way, and old ones have the old way, until they are updated. Right? --A D Monroe III (talk) 20:20, 2 August 2016 (UTC)

Countdown clocks
I presume that the use of templates such as countdown in articles would run afoul of MOS:DATED. Does anyone agree that there should be an explicit statement citing these as an example of something that needs to be avoided? ViperSnake151  Talk  00:32, 3 August 2016 (UTC)
 * If you can offer evidence that this has been an actual problem on multiple articles, such that editors are wasting time dealing with it, then maybe we should consider adding something on this point. Otherwise it's WP:CREEP; see this.  E Eng  03:34, 3 August 2016 (UTC)

Dateformat confusing
The way MOS:DATEFORMAT is presented is confusing. It is split into two tables: "Acceptable date formats" and "unacceptable date formats (except in external titles and quotes)". "Unacceptable date formats" then has separate "acceptable" and "unacceptable" columns. Are these actually, in fact, acceptable? What does it mean to be an acceptable unacceptable format? Acceptable only for "external titles and quotes"? ... &mdash;  Rhododendrites talk  \\ 16:16, 3 August 2016 (UTC)


 * If we were writing for computer scientists, and we had a well-controlled environment where nothing strange ever came up, we could just specify the acceptable formats with something like Backus–Naur Form and be done with it. But due to the varied background of our editors, and the weird situations which we occasionally have to write about, a less formal approach is more appropriate. The first table gives examples of acceptable formats. The second table explains, through examples, how close editors should come to the acceptable format. In the unacceptable date formats column, various examples are given in the unacceptable column, and suitable replacements are given in the acceptable column.


 * If you are inclined to try to improve this, please keep in mind that there is a lot of software out there checking date formats (notably the cite templates). The slightest change in meaning could upset a lot of stuff (and a lot of editors). I would suggest discussing any change here first. Jc3s5h (talk) 16:30, 3 August 2016 (UTC)
 * Hmm. Maybe it would be as simple as changing the column headings of the second table to something along the lines of "instead of this", "use this". Will give this some more thought later. &mdash;  Rhododendrites talk  \\ 18:53, 4 August 2016 (UTC)
 * Notice that (as an experiment -- I always think it's easier to evaluate things in situ) I interchanged the columns to put "Unacceptable" first, followed by "Acceptable", so that it follow the "Not this ... This instead" flow you mention.  E Eng  19:17, 4 August 2016 (UTC)

To include the day of the week or not to include the day of the week? That is the question....
At the moment, this MoS page doesn't comment on whether the day of the week should be included when giving dates in articles. OK, so through the examples it implies not. But sometimes the day of the week is included, and I can see that in some circumstances this might be desirable. But what are these circumstances? I think we need guidance on this. What are people's thoughts on the matter? — Smjg (talk) 20:39, 6 August 2016 (UTC)


 * I'd say, include the day of the week if it is relevant or useful to the point being made. Don't include it if it isn't.


 * It doesn't matter what day of the week someone was born, in general. But there is a weekly cycle, and for some events the position on that cycle is relevant.  If discussing a historical event in a European city, the fact that it happened on a Sunday may well have a significant bearing on the course of events.  And in some articles about events taking place over multiple days - the Olympics being a topical example - the day of the week might be a useful shorthand reference to avoid repeating date or day numbers over and over again. Kahastok talk 20:59, 6 August 2016 (UTC)


 * In general, it's immaterial and wasted space. But occasionally, the fact that something occurred on a local Sabbath or on the weekly payday is significant. The significance should be made clear in context, not just left hanging there. Whether this point deserves an MoS entry is debatable. Surely we can rely on the good sense of editors? --Pete (talk) 21:24, 6 August 2016 (UTC)
 * As usual, my first question is whether there's any evidence that MOS needs to opine on this. If editors are able to work this out on article Talk pages on their own without a lot of wasted time, then MOS doesn't need a rule on this. And as I'm fond of saying, if MOS does not need to have a rule on something, then it needs to not have a rule on that thing. (I agree with both K's and Pete's comments above, BTW.)  E  Eng  07:07, 8 August 2016 (UTC)
 * I've never seen it, and unless strongly relevant I'd mow it down. Tony   (talk)  06:08, 13 August 2016 (UTC)

SI prefixes and symbols "restricted"?
I'm not entirely sure about the phrasing here:


 * SI prefixes and symbols, such as giga- (G) and tera- (T), should be restricted to scientific, engineering, and technical uses.

given that most of the world's road signs use SI symbols such as "km" and most of the world's food packaging uses SI symbols such as "g" and "kg", I strongly dispute that the use of SI symbols is, in real life, "restricted to scientific, engineering, and technical uses". What I suspect this might have been trying to say was (in line with a point I made in a previous discussion) that SI symbols should not be used in a non-SI context. Thus, for example, no "megamiles (Mmi)", "kilopounds (klb)", "megadollars (MUSD)", since these are non-standard notations.

Would it be too bold to propose rewording the bullet along these lines, or have I completely missed something? As it stands, it suggests that every single occurrence of a measurement like "50 km" on Wikipedia is inappropriate, which is absurd. Most such measurements, I would suggest, are not found in technical contexts. I therefore propose rephrasing this as:


 * SI prefixes, such as giga- (G) and tera- (T), should be used only in SI expressions, such as 50 km, and not otherwise (e.g. 50 klb).

Archon 2488 (talk) 18:36, 2 June 2016 (UTC)


 * In context I don't think it's intended to mean that at all. It's not even in the section on units of measure.  In context (discussing treatment of large numbers) I think it's a rather over-sweepingly-worded rule that is intended to prevent use of high-magnitude prefixes/symbols such as giga- and tera-, that may not be known to the lay reader, in inappropriate contexts.  The same logic would also apply to low-magnitude prefixes/symbols such as nano- or pico-.


 * So for example, it rejects gigadollars (G$) in favour of "billion dollars", but also gigagrams ("million kilograms") and terajoules ("trillion Joules"). Kahastok talk 19:06, 2 June 2016 (UTC)


 * Fair enough. Although my point stands inasmuch as the original wording has got to go. Even if it's in a different section, we can't have wording which is so broad that it directly contradicts things that are said elsewhere in the MOS.


 * I thought we already had language to the effect that only units of an appropriate order of magnitude should be used. If this is all that's meant here, I am not sure what the additional benefit of such a rule could be. Units like picometres or terajoules will be used where they are conventional, and not otherwise; I would dispute that the diameter of an atom should be expressed in "trillionths of a metre" rather than picometres. Anyway, if we're going to say (as I suspect we should) that SI symbols belong with SI/metric units and not elsewhere (with possible additions like "Mya" where that is the conventional notation), then I suspect this bullet might be entirely pointless.


 * Regarding my original proposal, I now think that it might be better suited to the table in the section on measurements, under "Prefixes", since that is where the other rules about SI prefixes are. Archon 2488 (talk) 19:20, 2 June 2016 (UTC)


 * The diameter of an atom surely comes well within the range of "scientific, engineering, and technical uses".


 * I am not aware of any rule restricting units to an appropriate order of magnitude and wonder if that's workable. Difficult to see that the dollar is a useful order of magnitude for the National debt of the United States, but we basically bar all other alternatives.  I agree that the wording is overly broad, but the principle I outlined is sound I think.  If we are in a genuinely non-technical, non-scientific, non-engineering field I think we should prefer "... billion Joules" to "... gigajoules".  Real world example, we should be measuring the distance from Sydney to Perth in thousands of kilometres rather than megametres.


 * On your proposal, I am sceptical. I agree we shouldn't be inventing such units where they are not conventional - that is surely a more general rule, we should not invent units that don't exist in the real world - but if there is a field where they are conventional, we shouldn't refuse to use them. Kahastok talk 19:57, 2 June 2016 (UTC)


 * OK, sorry, that was a silly example. A better one would be that large volumes of water in Australia are commonly measured in units such as megalitres and gigalitres (I have no idea whether this counts as "technical"; one could argue that an article on economics such as the US national debt is "technical"). In any case, the rule should surely be to follow real-world practice here, rather than saying broadly "don't use large SI prefixes". I am not sure how often energy units of any sort are used in non-technical contexts, but in any case the real-world practice should be followed. Archon 2488 (talk) 21:08, 2 June 2016 (UTC)
 * The gas bill is in terajoules. But we never say "gigagrams" because a megagram is always called a tonne. Hawkeye7 (talk) 21:56, 2 June 2016 (UTC)
 * Indeed, that is another good example – megatonnes and gigatonnes (for example, in measuring explosions and carbon emissions). Archon 2488 (talk) 22:43, 2 June 2016 (UTC)


 * Perhaps we could get the point across with something like:


 * SI prefixes and symbols, such as giga- (G) and tera- (T), should not be used to express magnitude of numbers, except where forming common units of measure in the field discussed.


 * We could give examples like, they emitted 5 megatonnes of CO2, but Spending rose by G$5 per year.


 * I think most of the situations where this legitimately arises with large measures - including the desalination plant, the explosive capacity and the carbon emissions - could be characterised as within "scientific, engineering, and technical uses", but that does not resolve issues with the current wording apparently banning kilometres and kilograms and I could accept an argument that that stretches "scientific, engineering, and technical uses" somewhat beyond what is reasonable.  As an aside, personally I would have a preference for "billion litres" over "gigalitres" in the article on the desalination plant for clarity. Kahastok talk 18:28, 3 June 2016 (UTC)


 * I'd say get rid of the phrase entirely. It's only common sense to avoid these larger and smaller less well known prefixes in contexts where they might cause trouble.  What are these contexts exactly, though?  It doesn't seem that a simple rule could sort things out and "technical" is a bit vague.  The rule is likely to cause more confusion than clarity.  Just ditch this instruction creep.  Jimp 03:25, 4 June 2016 (UTC)


 * Tempted to agree with you, actually. Surely the default MOS rule should be that such weird nonstandard usage is not allowed; we shouldn't spell out specific cases unless there's evidence that there has been real confusion over this. I don't think I've ever seen notation like "G$" used anywhere on WP. Archon 2488 (talk) 14:21, 6 June 2016 (UTC)


 * Metric prefixes with currency symbols are problematic because they could be confused with country abbreviations, e.g. the "G" in "G$ 123" might stand for some country beginning with "G". Jimp 04:03, 30 June 2016 (UTC)
 * I G-agree.  — SMcCandlish ☺ ☏ ¢ ≽ʌⱷ҅ᴥⱷʌ≼  19:53, 15 July 2016 (UTC)

This:
 * SI prefixes and symbols, such as giga- (G) and tera- (T), should be restricted to scientific, engineering, and technical uses.

could be taken to imply that all SI prefixes are depreciated. In fact, from the kilogram and kilometre to the centimetre and the millimetre, they are used all the time. Perhaps this is what is meant:


 * The SI prefixes and symbols, (G) and tera- (T), should be restricted to scientific, engineering, and technical uses.

Here the meaning is restricted to the specified prefixes (which I hope is not too restrictive). Michael Glass (talk) 05:31, 2 August 2016 (UTC)


 * So, we can use petametres in non-scientific contexts but not terametres? Kahastok talk 20:11, 5 August 2016 (UTC)


 * I guess there would be a whole host of unusual prefixes that could be dragged out, so perhaps the point could be better expressed in this way:
 * Less used SI prefixes and symbols, such as giga- (G) and tera- (T), should be restricted to scientific, engineering, and technical uses.
 * This - or something like it - may get over the problem with the wording. Michael Glass (talk) 06:19, 8 August 2016 (UTC)


 * This seems like a sensible suggestion, with the necessary caveat that it's all context-dependent. For example, it should be obvious that the distance between New Zealand and the UK should be given as 18000 km, rather than (say) 18 Mm, in a general context – because "kilo" is the prefix normally used for expressing distances at these scales. For this reason, I am tempted by (although not strongly advocating) the view that this clause is not really necessary, and it can be left up to editorial discretion what is an appropriate prefix in each context – most of this stuff does not need to be spelled out at the MOS level, and attempting to do so only adds verbosity and gives a false impression of exhaustiveness. If there is evidence that the omission of such advice causes editors to disagree repeatedly, then we could always add it back, or add something to the units section about choosing the appropriate prefix for a given context and using it consistently.


 * Alternatively, if we decide to keep it, we could (and, I think, should) rephrase it to avoid the singling-out of giga and tera, which is illogical for the reason that Kahastok gives. Michael wants to remove "such as" because it's ambiguous (which is what I was originally complaining about). I think the gist of what we're trying to say is the same as the rule about not using the less-used prefixes such as hecto outside of the limited contexts where one encounters them. Moreover, we should remember that this sentence isn't in the units section of MOSNUM; it's talking about how to express quantities more generally. With that in mind, I think it would be best to rephrase this in a manner appropriate to the numbers (rather than units) section of the MOS, and simply say something to the effect that


 * SI prefixes and symbols, such as giga- (G) and tera- (T), should be used only with SI and other metric units as appropriate, and not to express large quantities in other contexts; do not write a population of 1.3G people.


 * Archon 2488 (talk) 12:40, 12 August 2016 (UTC)


 * As discussed earlier in this thread, we ought to allow SI prefixes on non-metric units in fields where this is common, such as with the light year. A wording that would allow this would be
 * SI prefixes and symbols, such as giga- (G) and tera- (T), should be used only with units of measure as appropriate to the field, and not to express large quantities in other contexts; do not write a population of 1.3G people.
 * Kahastok talk 17:11, 12 August 2016 (UTC)


 * Fair enough – I forgot about oddities like Mya, Gly, and so on. My main point was to emphasise that SI prefixes are for use with units, not in more general contexts. Archon 2488 (talk) 19:16, 12 August 2016 (UTC)
 * Sounds good to me, too. Michael Glass (talk) 09:37, 13 August 2016 (UTC)

Dashes in date ranges
Don't worry, I'm not going to re-open this discussion. I just want to ask about this:

Is there some reason not to just use a dash directly, like this?
 * 1881–1886

Seems more straightforward, and for me at least it's a lot easier to type. Kendall-K1 (talk) 13:20, 3 August 2016 (UTC)
 * inserts the ndash character so the two are equivalent.   doesn't get replaced with the ndash character until it is rendered by your browser.  For the purposes of use in cs1|2 templates (, etc) either '–' or  are acceptible;   is not.
 * —Trappist the monk (talk) 13:33, 3 August 2016 (UTC)
 * That's interesting, because Template:En dash says and   have "the same effect," which to me implies they can be used interchangeably. Kendall-K1 (talk) 14:17, 3 August 2016 (UTC)
 * I'll revise what I wrote. MediaWiki apparently converts   to '–' so it isn't the browser doing the work.  But, this conversion must happen after templates and modules are processed (which makes some sense).  To prove that it is MediaWiki doing the work:
 * Now, if you look at this page's html source, there should be three comma-separated ndashes in the source.
 * For cs1|2, inclusion of  in a date range would (were it allowed) corrupt the citation's metadata because the module would percent encode the html entity:  .  That could confuse consumers of the metadata.
 * —Trappist the monk (talk) 14:57, 3 August 2016 (UTC)
 * Either that, or the elite who maintain the templates could do whatever's necessary to make it so editors don't need to remember technical minutiae, and can just code the same way in templates that they do everywhere else. In answer to the OP's original question: mdash, ndash, and hyphen are very hard to distinguish in the edit window, so use of symbolics (e.g. ndash, &amp;ndash;) allows your fellow editors to see at a glance that the right mark is used, at the expense of some extra clutter.  E  Eng  16:11, 3 August 2016 (UTC)
 * In certain monospaced fonts the en dash looks very similar to the ASCII hyphen, so  might be hard to tell apart from   in the edit window. (Ideally we'd have   (two hyphens) automatically replaced with an en dash when rendering the page, the way TeX or Wordpress do, but I don't think that's going to happen at any time soon.) &mdash; A. di M.   12:52, 16 August 2016 (UTC)
 * —Trappist the monk (talk) 14:57, 3 August 2016 (UTC)
 * Either that, or the elite who maintain the templates could do whatever's necessary to make it so editors don't need to remember technical minutiae, and can just code the same way in templates that they do everywhere else. In answer to the OP's original question: mdash, ndash, and hyphen are very hard to distinguish in the edit window, so use of symbolics (e.g. ndash, &amp;ndash;) allows your fellow editors to see at a glance that the right mark is used, at the expense of some extra clutter.  E  Eng  16:11, 3 August 2016 (UTC)
 * In certain monospaced fonts the en dash looks very similar to the ASCII hyphen, so  might be hard to tell apart from   in the edit window. (Ideally we'd have   (two hyphens) automatically replaced with an en dash when rendering the page, the way TeX or Wordpress do, but I don't think that's going to happen at any time soon.) &mdash; A. di M.   12:52, 16 August 2016 (UTC)

question about WP:DATERET
Question regarding this bulletpoint: "The date format chosen by the first major contributor in the early stages of an article should continue to be used, unless there is reason to change it based on strong national ties to the topic or consensus on the article's talk page."

Assuming there is no clear argument for "strong national ties", can that "consensus on the article's talk page" be a simple matter of "I have a personal preference for this other format. Who agrees we should change it?" leading to a change based on a numeric majority of those responding to the poll? In other words, does there have to be a reason other than personal preference for the change? To me this seems like the sort of thing WP:DATERET should avoid (i.e. consensus is not a vote, and such a change should be based on weight of arguments rather than preferences of participants at a particular point in time). &mdash;  Rhododendrites talk  \\ 19:00, 4 August 2016 (UTC)


 * Pretty much everything on WP is ultimately decided by consensus, with the hope that those participating in discussion are guided by weight of arguments, policies and guidelines. "National ties" is not the only reason to prefer a date format, for example articles with US ties but military subjects often use military date formats. I think the wording here is fine. Kendall-K1 (talk) 20:48, 5 August 2016 (UTC)


 * Sure, but "consensus" isn't a vote count. It's about application of policies and guidelines. It doesn't seem like WP:DATERET would exist if personal preference were a perfectly valid reason to switch that only required a majority opinion in a straw poll. &mdash;  Rhododendrites talk  \\ 13:00, 16 August 2016 (UTC)

Use of CURRENTYEAR
I'm wondering about MOS:CURRENT. Several articles use the template currentyear. There are two issues: I "fixed" one example in Currency with diff, but now I'm unsure. The two choices follow.
 * The template should never be used; use the magic word instead, that is.
 * Some usages I saw seemed a bit contrived because references don't change each year.
 * As of July 2024, no country has an enforceable gold standard or silver standard currency system.
 * Wikitext:
 * As of July 2024, no country has an enforceable gold standard or silver standard currency system.
 * No country has an enforceable gold standard or silver standard currency system.

Any thoughts on what should be done with this text? It's not suitable for WP:ASOF, and an automatically changing date cannot be verified. However, the bare text (with no date) does raise questions for the reader—does that apply now? Johnuniq (talk) 05:21, 17 August 2016 (UTC)
 * Looks like a perfect case to use As of. The info is known at this point in time. Automatic update would introduce unverified content.  Pam  D  06:27, 17 August 2016 (UTC)

A clearer way to express one sentence.
The present proposal talks about units when it means weights and measures. This is not ideal. I suggest the following wording be changed:


 * Where English-speaking countries use different units for the same quantity, follow the "primary" quantity with a conversion in parentheses: the Mississippi River is 2320 mi long; the Murray River is 2508 km long

This could be expressed more clearly as this:


 * Where English-speaking countries use different measures, follow the "primary" measure with a conversion in parentheses: the Mississippi River is 2320 mi long; the Murray River is 2508 km long

This is shorter but clearer. Michael Glass (talk) 05:57, 2 August 2016 (UTC)


 * I disagree that weights and measures is clearer than units, and I wouldn't know what means "Where English-speaking countries use different measures" if it weren't embedded in this discussion.  E Eng  06:56, 2 August 2016 (UTC)


 * Yes weights and measures is too ponderous, but I think measures is clearer than units.. In the context of the sentence in question, the meaning is clear with the example that follows: "the Mississippi River is 2320 mi long; the Murray River is 2508 km long"

Another refinement of the wording could be as follows. Changes in wording are bolded:


 * As countries use different measurement units, follow the "primary" value with a conversion in parentheses: the Mississippi River is 2320 mi long; the Murray River is 2508 km long


 * 1) The direction applies to all countries, both English-speaking and not.
 * 2) The phrase measurement units is clearer than both measures and units
 * 3) Removing the phrase English-speaking is shorter and makes the point universally applicable.  Michael Glass (talk) 10:10, 3 August 2016 (UTC)


 * Michael, it's abundantly clear what "unit" means in this context, surely? Tony   (talk)  06:07, 13 August 2016 (UTC)
 * Units is clear in context (though, perhaps a little unusual in phrasing), but measurement units' puts the meaning beyond doubt. Michael Glass (talk) 09:44, 13 August 2016 (UTC)


 * It's perfectly clear what is meant by the current version and it does not need to change.


 * I note you've lost the meaning "for the same quantity" here, which is important. Context is vital here.  It is daft to insist on adding conversions where countries use different measurement systems, if in the context in question they all use the same one.  IMO, all of your versions lose clarity without providing any benefit whatsoever.  I thus oppose this change. Kahastok talk 19:07, 13 August 2016 (UTC)


 * I would partly echo Kahastok's skepticism on the merits of this. It's not immediately obvious why the proposed rewording is clearer; if anything it seems vaguer to me, and I do not see any substantive difference between it and the existing wording. Perhaps, Michael, you could give a concrete example of a case in which you think your proposed rewording would give editors some clarity that is lacking at present? I do not find "units" in this context confusing or ambiguous at all, and I understand what the sentence means on the first reading. Wording such as "units of measurement" would be more precise, but perhaps also unnecessarily more ponderous.


 * However, I note that the word "quantity" isn't used correctly in the current MOSNUM wording, because the physical quantity is the same regardless of how it is expressed. If a length is expressed as $2 1/2$ inches or 63.5 mm, the physical quantity – the length – is exactly the same. I would prefer to say "...follow the primary expression...", which is more pedantic but avoids this dubious use of the word "quantity". ("Measure(ment)" or "value" per MG's proposal might also work, but I believe "expression" is the most correct term for something like "2 km").


 * I assume the point of saying "English-speaking" is to preclude the use of units not commonly found in the English-speaking world, such as traditional Chinese units, Scandinavian mils, etc. There is clearly not much point in converting into systems of measurement which are not typically used in English-language contexts on the English-language Wikipedia. Archon 2488 (talk) 09:04, 15 August 2016 (UTC)


 * Thank you both for your feedback. The purpose of the suggested revision was not to change the meaning of the passage but to express it more concisely and clearly.
 * The phrase Where English-speaking countries use different measures, suggests that the policy applies only to English-speaking countries (though, as Archon pointed out, it could also preclude the use of foreign units.) The wording could be refined like this: As English-speaking countries use different units of measure... This wording applies more specifically to the measures used in English-speaking countries.
 * Units, by itself is not clear. It could be replaced with units of measure.
 * The phrase for the same quantity as Archon has pointed out, does not use the word quantity correctly. It also becomes redundant as you only use different units of measure when people actually do use them. As the phrase is both redundant and ungrammatical, it is better to remove it.
 * The word quantity is misapplied, as it relates to volume rather than linear measures, like miles and kilometres, or acres and square miles.


 * I think it is better to compare the proposal beside the present wording (which comes first). Changes in wording are bolded. The phrase for the same quantity is omitted because it is both redundant and ungrammatical:


 * Where English-speaking countries use different units for the same quantity, follow the "primary" quantity with a conversion in parentheses: the Mississippi River is 2320 mi long; the Murray River is 2508 km long
 * As English-speaking countries use different units of measure, follow the "primary" measure with a conversion in parentheses: the Mississippi River is 2320 mi long; the Murray River is 2508 km long


 * I think the suggested revision, or something like it, would lose nothing in meaning from the present wording, but would be shorter, clearer and less liable to be misunderstood. Michael Glass (talk) 10:31, 16 August 2016 (UTC)


 * The meaning of "Where English-speaking countries use different units for the same quantity" is still lost in this, and I remain unconvinced of any need for change here. Kahastok talk 18:44, 16 August 2016 (UTC)
 * Ditto. This seems like a fix in search of something broken.  E Eng  20:01, 16 August 2016 (UTC)
 * If the whole article/section is about units of measurement, then it's obvious from context. That is, "units" is quite enough.
 * An analogy: If you're talking about New York City, it's unnecessary to say "Central Park in New York City is bounded on the north by 125th St. in New York City, on the east by Fifth Ave. in New York City, on the south by 59th St. (Central Park South) in New York City, and on the west by Eighth Ave. (Central Park West) in New York City." OK, that's ridiculous; but you don't even need to say "Central Park in New York City is bounded on the north by 125th St., on the east ..." You're talking about measurements, so you don't need to say "" "units ". --Thnidu (talk) 23:09, 16 August 2016 (UTC)
 * So in your opinion commenting here at the talk page of the English Wikipedia Manual of Style/Dates and Numbers, the English Wikipedia Manual of Style/Dates and Numbers need not specify that the English Wikipedia Manual of Style/Dates and Numbers is talking about how editors of the English Wikipedia should deal with dates and numbers?  E Eng  23:38, 16 August 2016 (UTC)
 * I'll accept units or, better, measures instead of units of measurement but the use of the word quantity in the present wording is still wrong. You don't have a quantity of miles or a quantity of square kilometres. That's nonsense. That wording is broken and needs to be fixed. Michael Glass (talk) 03:59, 17 August 2016 (UTC)
 * I think "for the same quantity" is essential to the meaning, as Kahastok says; it is not ungrammatical or illogical in this context. For example, if the quantity we're talking about is area, then units such as hectares, acres, or square kilometres would be appropriate units. You are correct that the phrasing "a quantity of square kilometres" is not sensu stricto correct (although it is not used in MOSNUM), given the scientific use of the term "quantity" (which means roughly "a physical property, with or without dimension, that can be measured"). Thus you can have a "quantity of apples" (say, five – a dimensionless and unitless number because you're just counting stuff), and a "quantity of land" (which has the dimension of area and units such as square kilometres), but not "a quantity of area", which means something like "a quantity of a quantity". This is also the sense of "quantity" used in the International System of Quantities. I do, however, separately object to the phrasing "follow the primary quantity", for the reason I gave above. When you present a conversion, you are showing two expressions of the same quantity. For example, the SI expressions "2×106 m2" and "2 km2" express the same area, i.e. the same quantity. I think we are in agreement on this point.


 * I take Kahastok's point to be that if you omit "for the same quantity", it implies (on a strict reading) that, if two English-speaking countries use different units at all, then conversions are necessary, even if they are not relevant to the context (e.g. electric potential, where everyone always uses the same unit). Moreover, you've still not explained in what cases the existing wording is likely to be misunderstood.


 * All of this, of course, is quite pedantic, and a common-sense reading of the sentence gives only one reasonable interpretation. Archon 2488 (talk) 09:11, 17 August 2016 (UTC)


 * In that case, keep the phrase for the same quantity. However, we don't convert a quantity, we convert a measurement. Changing one word can fix that:


 * Where English-speaking countries use different units for the same quantity, follow the "primary" measure with a conversion in parentheses: the Mississippi River is 2320 mi long; the Murray River is 2508 km long


 * This preserves all the meaning of the sentence but deals with the anomalous use of quantity. We don't convert the quantity, we measure (or take the measurement supplied ) and then we convert it to miles or acres or whatever. Michael Glass (talk) 02:54, 18 August 2016 (UTC)

This really is getting grossly pedantic. Most editors will be confused by the idea of "measures". Please give an example of an actual article-editing situation in which the current wording led to a problem of some kind.  E Eng  03:44, 18 August 2016 (UTC)
 * I think you've missed the point. The problem is with the wording, that confuses quantity with measurement. If I poured you a pint of beer, the quantity of beer would not change whether we measured it in mils or pints. If the word measures is likely to confuse editors, why not use measurements instead?


 * Where English-speaking countries use different units for the same quantity, follow the "primary" measurement with a conversion in parentheses: the Mississippi River is 2320 mi long; the Murray River is 2508 km long


 * Of course, this does not preclude refining the wording further. Michael Glass (talk) 06:17, 18 August 2016 (UTC)


 * No, I haven't missed the point. This isn't the Journal of the National Institute of Standards and Technology. To the layman, talk of multiple "measurements"/"measures" makes it sound like you took the patient's blood pressure multiple times, getting slightly different readings each time and so on. Again I challenge you to point to any article-editing situation in which the current wording has led to difficulties.  E Eng  07:31, 18 August 2016 (UTC)


 * Thank you for your feedback. I'll try to respond to the points you made.
 * You expressed concern about using the word measures; I responded by substituting the more common word, "measurements." Thank you for this feedback.
 * The word measurement is only used once but you said it sounds like multiple blood pressure measurements. I can't see how a single use of a singular word can imply the plural.
 * In the wording at present, the word quantity is used twice but nobody suggests it implies a double dose of drugs. Similarly, my single use of the word measurement has nothing to do with multiple blood pressure readings.
 * "I done it myself," is clear but incorrect; "I did it myself," is clear but correct. Similarly, "Follow the "primary" quantity with a conversion in parentheses," might be clear but it's incorrect; A quantity of iron ore might be turned into steel and a quantity of scraps into compost, but we don't convert a quantity of distance into miles or kilometres or a quantity of acres into hectares. We convert the measurements. "Follow the "primary" measurement with a conversion in parentheses," is both clear and correct.
 * You say this isn't the Journal of the National Institute of Standards and Technology. Was that the Journal of Research of the National Institute of Standards and Technology? Just because Wikipedia is not a peer-reviewed journal, we still need to get things right.
 * I can't point to any article editing situation where the current wording has led to difficulties or where changing one word would lead to difficulties, either. All it would do is to make the wording more precise.
 * However, I don't want to claim that my suggestion (see below) could not be improved on.
 * Where English-speaking countries use different units for the same quantity, follow the "primary" measurement with a conversion in parentheses: the Mississippi River is 2320 mi long; the Murray River is 2508 km long
 * Michael Glass (talk) 12:13, 18 August 2016 (UTC)

Was that the Journal of Research of the National Institute of Standards and Technology? No, it was just something I made up. And no, we don't have to get that right here in this now-borderline-absurd discussion. That you seem utterly serious about your #5 above shows that you can't see the forest for the trees. I've boldly changed --
 * Where English-speaking countries use different units for the same quantity, follow the "primary" quantity with a conversion in parentheses

-- to read --
 * Where English-speaking countries use different units for the same quantity, provide a conversion in parentheses

-- thus sidestepping the question of whether we should say measurement or measure or quantity or whatever. Since you say you know of no examples of the current wording causing an actual problem for actual editors, you're wasting everyone's time.  E Eng  21:01, 18 August 2016 (UTC)
 * You admitted making up a bogus journal name to make a rhetorical point.
 * You accused me of "sidestepping" about whether we should have measurement or measure when I changed to measurement because of your feedback.
 * Do you think your bogus reference and your misrepresentation of my position was not a waste of everyone's time? Please, | don't come the raw prawn.
 * I note that today you changed the wording and removed the difficulty that I drew attention to. Good, but you could have done it without the nastiness. Michael Glass (talk) 09:55, 19 August 2016 (UTC)
 * Yeah, I "made up a bogus journal name to make a rhetorical point". That wastes no time except to the extent you keep acting like there's something wrong with doing that.
 * I didn't accuse you of sidestepping anything. I said I made an edit  which sidesteps the non-problem you're so hung up on.
 * I didn't change my mind about anything. I simply removed the phrase whose wording you've been agonizing over for weeks, because it doesn't need to be there at all.
 * Unless you (or someone else) objects to the edit I've made, I won't be responding further, so please go ahead and have the last word now.  E Eng  16:43, 19 August 2016 (UTC)
 * Just to clarify things: I thanked you for your edit to MOSNUM and I meant if. And yes, I did misread what you wrote, and I apologise for that. However, your bogus citation did send me on what turned out to be a wild goose chase, which was annoying. However, the main thing is that the wording of MOSNUM has been improved. That makes it worthwhile. In future, let's hope that we can work better together, without the rancour. Michael Glass (talk) 09:27, 20 August 2016 (UTC)


 * Oh come off it Michael. The only one accusing people of things here is you.   And your going on about a "bogus journal name" like he'd done something evil when it was blindingly obvious that he was just making a rhetorical point is absurd and frankly disruptive.  There is nastiness here but you're the one supplying it.  The rest is just exasperation at this absurdly unnecessary pedantry. Kahastok talk 16:47, 19 August 2016 (UTC)
 * Kahastok, first of all I'd like to thank you for | this edit. It made the policy clearer. Next I would like to acknowledge that you made two contributions to this discussions without rancour. and . However, your last contribution was not helpful. In fact, I regard it as bullying, which really is disruptive.. The main thing, however, is that MOSNUM has been improved. Let's just concentrate on that and move on. Michael Glass (talk) 09:27, 20 August 2016 (UTC)

Unit conversions in science articles
The MOS states " In science-related articles, however, supplying such conversion is not required unless there is some special reason to do so." What is meant by this? In every FAC or GA about animals (science) I've nominated, I've been asked to add conversions. What is a "special reason? And what is not a "special reason"? Seems extremely ambiguous/arbitrary. FunkMonk (talk) 09:09, 18 May 2016 (UTC)


 * It means that for most articles, if you report a power measurement as 10 W, you don't need to provide a conversion to BTU/h. Or if you report an asteroid size as 20 km, you don't need to convert to miles. A 'special reason' would be the article is of high general interest, like in the case of Jupiter where its size is given in both km and miles, or if the dimensions of a certain piece of equipment is standard in non-SI unit, like a 2.54 cm (1 in) diameter rod. Headbomb {talk / contribs / physics / books} 09:20, 18 May 2016 (UTC)
 * But why the exception? Isn't it always relevant to show these conversions (at least dimensions and weight, helpful for any reader), regardless of whether it is a science article or not? Again, seems very arbitrary. FunkMonk (talk) 09:23, 18 May 2016 (UTC)
 * Because sometimes conversions help. But plastering them all over the place isn't good. In astronomy, for instance, galaxies sizes and distances are measured in parsecs and conversions often given in lightyears. But having "M31 is located 780 kiloparsecs ($2.5 ly$, $2.4 m$, $1.5 mi$) from earth." is fairly pointless, given no one has an intuitive idea of just how big any of those numbers are. These are astronomical distances, and the most we can expect of readers is that some of them will remember that the nearest star is 4 light years away. The km or mile value of that distance adds nothing to the understanding, but this is also why we link the first instance of those non-SI units (someone can always check how big one parsec is in km or mile if they really want to). Headbomb {talk / contribs / physics / books} 09:48, 18 May 2016 (UTC)
 * In that case, the MOS text is misleading. If the specific problem is only with huge distances, very technical units, etc, that should be the exception ("special reasons"). Science articles as a whole should not be a general exception. We're now in a situation where for example the size of organisms, the weight of small meteors, etc, are somehow exempt from conversion, for no good reason. FunkMonk (talk) 09:56, 18 May 2016 (UTC)
 * Not really. If you write a "$10 um$ wide bacteria", you shouldn't convert that to thous. Nor the mass of meteors reported in slugs. Science is done in SI, 90% of the time, and conversions aren't needed except in special cases. Headbomb {talk / contribs / physics / books} 10:09, 18 May 2016 (UTC)
 * Ok, let's be more specific then. Animal, plant, and anatomy articles, which we have tens of thousands of (a considerable percentage of our science articles, therefore hardly "special cases"). Why are they exempt? If they aren't, we need to state what exactly is considered "special reasons", otherwise we leave too much room for interpretation. Or we could say that some non-technical units, such as metres, kilos, etc, should always be converted. FunkMonk (talk) 10:13, 18 May 2016 (UTC)

FunkMonk, there may very well be room for clarification here. To make the discussion concrete, can you give us two or three specific article passage you're concerned about, explaining how this MOS provision isn't clear with regard to how they should be treated?  E Eng  11:51, 18 May 2016 (UTC)
 * This GAN discussion about the dimensions of a fossil egg (bullet point 10, which is what brought me here) gives a pretty specific example of how the ambiguity creates a problem: In this case, the measuerement is so small that it is probably fine. But I have never seen anyone bring that guideline up before in this context, but nothing stops it from happening henceforward and in more general contexts. FunkMonk (talk) 12:01, 18 May 2016 (UTC)
 * Hmmmm. Where the dimensions of the egg are described it seems useful for the general reader, if he happens to be unmetricated, to get a conversion to inches -- these are big, big eggs and the reader should get an idea of how big. But by the time we get to the thickness of the shell, while that's important for people who work with dinosaur shells, I'm not sure it tells the lay reader much to convert that to thousandths of an inch or whatever.


 * On the other hand, what does it hurt to do so anyway? I think it hurts nothing, except in a heavily technical article, with many measurements of a kind that laymen won't appreciate anyway, in which case perhaps the constant interruption for conversions becomes tiresome.


 * So in the example you give, I'd convert everything. If I'm right in what I say above, then the wording should be adjusted. But this just preliminary thinking on my part. Others' thoughts?
 *  E Eng  13:10, 18 May 2016 (UTC)
 * P.S. Changed my mind on my point above that "I'm not sure it tells the lay reader much to convert that to thousandths of an inch or whatever". At the GA review, someone said, "people generally don't have an intuition for how small 0.043 inches is, even if inches come more naturally to them that metric units". That makes me realize how useful such a conversion actually is. I'm sorry to say I'm one of the Great Unwashed and Unmetricated, so that inches do come most naturally to me; but I also have a technical background, so when I see 0.043 inches, I can immediately say, "Hmmm, yes, that's a bit less than 1/20 of an inch", and that's useful to me.
 * Yeah, my point is that nothing in the guideline makes clear what is considered a "special reason", and that it is so ambiguous and arbitrary as to be useless. In theory, could we deny conversion for the weight of an elephant? The guideline doesn't specify whether that is a "special case" or not. FunkMonk (talk) 13:18, 18 May 2016 (UTC)
 * Let us hope our esteemed fellow editors contribute a few more actual-article examples as food for thought. From that may come a crystallization of our thinking on possible changes to the guideline's wording.  E Eng  13:48, 18 May 2016 (UTC)
 * I don't know the turnover rate of this talk page, but I fear this section will be archived before that happens... FunkMonk (talk) 14:02, 18 May 2016 (UTC)
 * You'd be surprised. It's a worthy topic. Anyway, the bot's set to leave a minimum # of threads around indefinitely. Be patient.  E Eng  14:37, 18 May 2016 (UTC)

Picking up on the mention of plant articles above, it's clear that many US readers want customary units for the dimensions of plants, so at least for those plants found in North America, it's common to provide conversions. This seems reasonable to me; whether it should be spelt out in the MoS I'm not sure. Peter coxhead (talk) 17:30, 18 May 2016 (UTC)
 * While we're on the subject of conversions, is there any progress on converting acres to km^2 instead of (or as well as) to hundredths of Christopher Robin's blessed wood? Dondervogel 2 (talk) 19:25, 18 May 2016 (UTC)
 * And btw I'd gladly provide an example of whatever it is you are looking for examples of, but I'm not sure what that it is. Is it conversions missing where they are needed, present when not, present when needed, absent when not, or none of the above? Dondervogel 2 (talk) 19:29, 18 May 2016 (UTC)


 * Surely Wikipedia should use hectares, rather than Km^2, to convert acres? A hectare is just under two and a half acres, whereas a square kilometer is nearly 250.  But what do I know?  I'm an American, and unschooled in the mysteries of the metric system. (I do know, however, with all due respect, that Christopher Robin's Hundred-Acre Wood does not deal in hundredths.)  J. D. Crutchfield &#124; Talk 21:48, 18 May 2016 (UTC)
 * We always use hectares to convert acres. Square kilometres is used to convert square miles. Hawkeye7 (talk) 23:30, 18 May 2016 (UTC)
 * I think what we need are examples, drawn from your experience, where what seems to be a good decision about whether to convert or not convert is in tension with the current wording, "In science-related articles, however, supplying such conversion is not required unless there is some special reason to do so". So far, I'm tentatively convinced that, even in "science-related articles", the general description of a plant or animal should usually be converted, so that laymen can envision the organism.  E Eng  22:26, 18 May 2016 (UTC)
 * The main purpose of conversion is to maintain faith with the original sources when they are using the old measurements. Everybody should know metric; it's used in nearly every country and even in the United States it is part of the common core. While my father would still measure the height of a horse in hands and its weight in stones, I don't know if that would be worth the effort for the majority of readers. Hawkeye7 (talk) 23:43, 18 May 2016 (UTC)
 * No, the main purpose of conversion is to ensure that a reasonably large %age of readers have an intuitive understanding of at least of the units in which a measurement is presented. I'm sorry, but while I agree everyone "should" know metric, but the fact is that most in the US don't (your talk of common core notwithstanding -- most US high school students take X years of a foreign language, but that doesn't mean we should present articles in Spanish, French, or German only, expecting them to understand one of them).  E Eng  00:45, 19 May 2016 (UTC)
 * The Large Hadron Collider uses extensively (km to miles, metres to feet, Kelvin to centigrade, m/s to mph, Mega Joules to tons of TNT), which all seem to be eminently sensible conversions to include.
 * The example above concerning parsecs (at Andromeda Galaxy) converts parsecs/light years/astronomical units and metres to inches (telescope size), but doesn't convert 218-ft to metres (size of Transit Telescope) which would be an improvement.
 * Supercooling consistently converts temperatures in Kelvins to centrigrade and fahrenheit.
 * Celsius, not centigrade. Hawkeye7 (talk) 23:43, 18 May 2016 (UTC)
 * There is absolutely nothing wrong with "centigrade" in the English language. I can't imagine what utility was meant by the above comment. RGloucester  — ☎ 03:02, 19 May 2016 (UTC)
 * -- (signed) Disgusted of Tunbridge Wells 07:17, 19 May 2016 (UTC)
 * "Centigrade" is purely historical. It was renamed "Celsius" in 1948. Hawkeye7 (talk) 08:40, 19 May 2016 (UTC)
 * It doesn't matter what some trifling international organisation has named anything. People use it, and there is nothing inherently wrong about it. It was renamed for reasons unrelated to its English usage. Meaning is conveyed without ambiguity, and hence there is absolutely no reason to stick up one's hand in such a swashbuckling manner. Please consider others before going on such tirades. RGloucester  — ☎ 13:36, 19 May 2016 (UTC)
 * -- (signed) Disgusted of Tunbridge Wells 02:26, 20 May 2016 (UTC)
 * Looking around for some biology examples I came across Histology where the sections Processing - dehydration clearing and infiltration and Sectioning use namometres and micrometres without any conversion (or any comparative objects - see 1 micrometre and 100 nanometres for possible comparisons), but does note that 1000 micrometres = 1 mm. The article uses values around 5 micrometre - maybe not a particularly useful conversion but I can get a bit of a sense of that - it's one fifth of a thou (thousandth of an inch - the thinnest blade in car mechanic's imperial feeler gauge set).
 * It does seem to me that the scientific articles that do include appropriate conversions are more understandable than those that do not. Even being more than semi-metricated and semi-washed I find still find it useful to know the thickness of the eggshell mentioned above is about 40 thou - that gives me a very good idea of how thin the eggshell is... Robevans123 (talk) 23:32, 18 May 2016 (UTC)


 * Guilty as charged: I was the one who pushed for the optional exclusion of British Empire (i.e. US) units in scientific articles, waaaaaay back a decade ago. Please, doesn't every single American schoolkid have exposure to the international system? The clutter factor can become really intrusive in some science articles. Tony   (talk)  07:34, 19 May 2016 (UTC)
 * I see. But isn't "clutter" (including in-text explanation of terms) a necessary evil to make complex articles understandable for layeaders? And shouldn't exclusion of conversions be the exception rather than the rule? FunkMonk (talk) 08:02, 19 May 2016 (UTC)


 * Tony, Exposure isn't facility. I absolutely understand about clutter -- you'll see I mentioned it above. I just think "not in science-related articles... unless there is some special reason" is too sweepingly discouraging of conversions in e.g. descriptions of the visible appearance of familiar animals. Maybe instead "not in technical [or "highly technical"?] sections of article, unless there's some special reason"? Added after edit conflict... And I think, in general, excluding conversions should be the exception, though I'd make it clear it's very much a question of editorial discretion, lest we create a new class of those annoying script-equipped MOS-compliance stormtroopers.  E Eng  08:11, 19 May 2016 (UTC)
 * It seems to have more to do with the Wikipedia writers than the readers. The former are about 20 years older than the latter on average, and therefore far more familiar and comfortable with the old measurements. To the younger generation, they are merely used in figurative expressions, without real physical meaning. Just as we still say "penny wise, pound foolish" without knowing how many pennies there was to the pound. Hawkeye7 (talk) 08:40, 19 May 2016 (UTC)
 * I must object strongly to the previous statement! Despite the jokes about metrication I'm perfectly comfortable with SI units, and if necessary, can do quick "back of a fag packet" calculations in my head to convert units and large and small dimensions into "understandable" quantities. I'd cope quite well if wikipedia was SI only. What I do try to do is use my knowledge of both SI and imperial systems and metrology in general to work out what might be useful to readers - especially US readers who are more familiar with the US customary units. Yes - the US has adopted SI for science and to an extent for engineering. That does not mean that the "average American reader" (regardless of age) is particularly comfortable with SI units (unless they are from an engineering/scientific background).


 * Back to the main discussion... I actually found it quite hard to find "scientific articles" that had lots of units (with or without conversions) - easier to find in engineering/archictecture articles. I agree with EEng's comment that the current statement is "too sweepingly discouraging of conversions". As far as SI units go, we're talking mainly about the base units for mass, length and temperature, and some of the derived units (newtons, pascals, and joules). All of these can be usefully converted in scientific articles (with the proviso that "highly technical" sections, or sections with lots of measurements don't need to be converted). I'd prefer to see this as one of the bullet points in the MoS rather than a qualifier in the starting paragraph.


 * Incidentally, looking at the various articles has emphasised how important consistency is (Andromeda Galaxy flits wildly in using parsecs/light years/astronomical units as the main unit), and how important it is to provide some context of size in articles dealing with the very large and very small. Robevans123 (talk) 09:44, 19 May 2016 (UTC)


 * SIR – Your gratuitous reference to homosexual genitalia mars an otherwise valuable and informative post. —‌(signed) Disgusted of Tunbridge Wells
 * Thank you! I never thought I'd laugh out loud at a discussion in MOS:Dates and formats. I shall be renewing my subscription to this esteemed organ. Robevans123 (talk) 12:26, 19 May 2016 (UTC)
 * Enjoy it while you can, because soon some dyspeptic killjoy will appear to remind us that "We are not here for your entertainment" and "what you think as amusing may not be to others" .  E Eng  13:37, 19 May 2016 (UTC)
 * Urgent comment on previous: "fag" doesn't refer to "homosexual genitalia"; but to (male) homosexuals. It's typically derogatory, if not used ironically or mock-humourously. Tony   (talk)  11:45, 20 May 2016 (UTC)
 * Tony, you're obviously not up on your gay slang. Follow both links in my SIR post above. —‌(signed) Disgusted of Tunbridge Wells
 * Ooh, my favourite! Black mm (ins). Martinevans123 (talk) 08:29, 11 June 2016 (UTC)
 * Let me asking you something, ME123. At family holidays, did they let you eat at the grownups' table?  E Eng  12:20, 11 June 2016 (UTC)
 * Only the grown-ups go. The last time I was allowed, someone said something about me being one sandwich short of a full picnic. It's quite dark in this cellar, you know. Martinevans123 (talk) 17:06, 11 June 2016 (UTC)


 * Seeing as I wrote the text which sparked this discussion, I feel like I ought to chime in. My reasoning for excluding conversions on the millimeter measurements was that these numbers are very small in inches (for example, 1.1 mm is 0.043 in), and add a lot of clutter to the page. When I'm reading an article, I find that conversions everywhere make it more difficult to read, but I understand the necessity in many cases. Being an American, I find inches much more intuitive than millimeters or centimeters, but for very small amounts, like 1.1 mm (0.043 in), the number 0.043 in doesn't really give me an idea of how small that is. However, according to EEng, it does give some readers who wouldn't intuit 1.1 mm an idea, so I think I will include the conversion on "my" page (Cairanoolithus) and I agree with EEng that "in general, excluding conversions should be the exception, though I'd make it clear it's very much a question of editorial discretion". Ashorocetus (talk &#124; contribs) 14:20, 19 May 2016 (UTC)


 * So getting back on track, it seems most here can agree that exclusion of conversions should be the exception rather than the rule? Or are there any dissenters? FunkMonk (talk) 15:41, 20 May 2016 (UTC)
 * The best way to get concrete opinion is to make a concrete proposal for changed guideline wording. (I lack the concentration just now to do that myself.)  E Eng  15:57, 20 May 2016 (UTC)
 * By simply re-jigging the current text, I get: "In science-related articles, however, supplying such conversions is not required in special/some cases." Could be followed by an example or two and a rationale: "Highly technical sections with many measurements can become too cluttered if they are all accompanied by conversions. "Clutter" isn't even mentioned in the current text, even though it seems to be the only argument against conversion. And yes, it would work better as a bullet point. FunkMonk (talk) 16:01, 20 May 2016 (UTC)

Proposal A1
Let me suggest that we focus more on the "technical" and "dense" criteria, instead of the vague "science-related".


 * Where English-speaking countries use different units for the same quantity, follow< the "primary" quantity with the "primary" quantity should usually be followed by a conversion in parentheses: the Mississippi River is 2320 mi long; the Murray River is 2508 km long. In science-related articles, however, supplying such conversion is not required unless there is some special reason to do so. 
 * In technical articles, sections, or passages dense with measurements, conversion of every measurement may be of little value and can clutter the text. In such cases editorial judgment will dictate which measurements should and should not carry conversions.
 * Where an imperial unit is not part of [etc etc]

 E Eng  19:07, 20 May 2016 (UTC)
 * Looks good to me. Robevans123 (talk) 19:11, 20 May 2016 (UTC)
 * -- (signed) Satisfied in Southampton.  E Eng  19:21, 20 May 2016 (UTC)
 * Second that. FunkMonk (talk) 20:04, 20 May 2016 (UTC)
 * -- (signed) Seconding in Schenectady.  E Eng  23:26, 20 May 2016 (UTC)

Proposal A2
This refines A1 a bit, and adds an example. The strikeout/underlining is still vs. the current live guideline. The animal example is made up. The semiconductor example is a bit awkward (but maybe that's the point). Improvements welcome! (Modify in place if the change is immaterial to comments anyone's made.)


 * Where English-speaking countries use different units for the same quantity, follow< the "primary" quantity with the "primary" quantity should usually be followed by a conversion in parentheses: the Mississippi River is 2320 mi long; the Murray River is 2508 km long. In science-related articles, however, supplying such conversion is not required unless there is some special reason to do so. 
 * In scientific/technical articles, sections, or passages dense with measurements, conversion of every measurement may clutter the text to little benefit. In such cases editorial judgment will dictate which, if any, measurements should carry conversions.
 * &bull;  Adults are typically 13–17 cm (5–7 in) long, with blue or orange eyes, razor-sharp teeth, and a tail 5–8 cm (2–3 in) long.
 * Typical sizes were about 10 µm (0.0004 in) in 1971, but decreased rapidly through the 1980s (1500–800 nm), 1990s (600–180 nm) and 2000s (130–32 nm). By 2014 sizes as small as 14 nm (0.55 millionths of an inch) were common.
 * Where an imperial unit is not part of [etc etc]

 E Eng  00:10, 22 May 2016 (UTC)


 * The semiconductor example is exactly where conversions should not be used. &mu;m and nm to inches? Makes as much sense as converting Earth mass into slugs. Headbomb {talk / contribs / physics / books} 01:33, 22 May 2016 (UTC)
 * Well, like I said, I know it's awkward. My idea was that sometimes you might convert the first measurement in a series of similar measurements (which, actually, these aren't -- they run through orders of magnitude) to give the reader a sense of size, and then don't bother with the rest. Or in this case, I thought it might make sense to convert the two endpoints, again to let the Imperial numbskull at least grasp how things have progressed; but it just ends up a mess with "millionths of an inch" and so on. Like I said, Improvements welcome!, so please contribute something better. Do you like the orange-eyed creature, though?  E  Eng  02:23, 22 May 2016 (UTC)
 * P.S. As a gesture toward sanity, A3 removes the conversion of the right endpoint...

Proposal A3

 * Where English-speaking countries use different units for the same quantity, follow< the "primary" quantity with the "primary" quantity should usually be followed by a conversion in parentheses: the Mississippi River is 2320 mi long; the Murray River is 2508 km long. In science-related articles, however, supplying such conversion is not required unless there is some special reason to do so. 
 * In scientific/technical articles, sections, or passages dense with measurements, conversion of every measurement may clutter the text to little benefit. In such cases editorial judgment will dictate which, if any, measurements should carry conversions.
 * &bull;  Adults are typically 13–17 cm (5–7 in) long, with blue or orange eyes, horrid breath, razor-sharp teeth, and a tail 5–8 cm (2–3 in) long.
 * Typical sizes were about 10 µm (0.0004 in) in 1971, but decreased rapidly through the 1980s (1.5 µm – 800 nm), 1990s (600–180 nm) and 2000s (130–32 nm). By 2014 sizes as small as 14 nm were common.
 * Where an imperial unit is not part of [etc etc]

 E Eng  02:38, 22 May 2016 (UTC)

Proposal A4

 * I love the halitotic, polychromatic bug! The example works.
 * The second example uses orders of magnitude which confuses the issue. BTW the discussion is also confused by references to slugs - a relatively obscure unit of measurement used only by imperial scientists and engineers. I suspect that the majority of fully metricated readers will also struggle with micrometres and nanometres and, at least on first usage, would probably benefit from a conversion into more familiar units, eg 1 µm (one thousandth of a millimetre, 0.001 mm, or about 0.000039 inch). But that perhaps is outside the scope of this discussion. How about:
 * &bull;  Popular model gauges are 6.5 mm (​0.256 in), 9 mm, 12 mm, 16.5 mm, 30 mm, and 45 mm (1.77 in).

Robevans123 (talk) 09:23, 22 May 2016 (UTC)
 * No conversions from within the SI system to SI system. That's why we have SI prefixes in the first place! Headbomb {talk / contribs / physics / books} 13:11, 22 May 2016 (UTC)
 * What are you talking about?  E Eng  13:18, 22 May 2016 (UTC)
 * To quote Robevans123: "I suspect that the majority of fully metricated readers will also struggle with micrometres and nanometres and, at least on first usage, would probably benefit from a conversion into more familiar units, eg 1 µm (one thousandth of a millimetre, 0.001 mm, or about 0.000039 inch)." Headbomb {talk / contribs / physics / books} 14:18, 22 May 2016 (UTC)

Way better! So now we have:


 * Where English-speaking countries use different units for the same quantity, follow< the "primary" quantity with the "primary" quantity should usually be followed by a conversion in parentheses: the Mississippi River is 2320 mi long; the Murray River is 2508 km long. In science-related articles, however, supplying such conversion is not required unless there is some special reason to do so. 
 * In text dense with measurements, conversion of every measurement may add clutter to little benefit. In such cases editorial judgment will dictate which, if any, measurements should carry conversions.
 * &bull;  Adults are typically 13–17 cm (5–7 in) long, with blue or orange eyes, horrid breath, razor-sharp teeth, and a tail 5–8 cm (2–3 in) long.
 * &bull;  Popular model gauges range from 6.5 mm (​0.256 in) to 45 mm (1.77 in).
 * Popular model gauges are 6.5 mm (​0.256 in), 9 mm, 12 mm, 16.5 mm, 25 mm, 30 mm, and 45 mm (1.77 in).
 * Where an imperial unit is not part of [etc etc]

Notice I also cut down the "In scientific/technical articles" bit -- I don't think it's needed -- and elaborated the second example for better contrast.  E Eng  10:30, 22 May 2016 (UTC)
 * I think we're getting there. I'd be Delighted of Tunbridge Wells with that. Robevans123 (talk) 11:14, 22 May 2016 (UTC)

Proposal A5
Incorporating some good ideas from B1 (below). The football example, um, didn't turn out as good as I'd hoped, but you get the idea. Maybe someone can improve it, or work up a better example.


 * Where English-speaking countries use different units for the same quantity, follow< the "primary" quantity with the "primary" quantity should usually be followed by a conversion in parentheses: the Mississippi River is 2320 mi long; the Murray River is 2508 km long. In science-related articles, however, supplying such conversion is not required unless there is some special reason to do so. 
 * However, in certain circumstances conversion is inappropriate:
 * &bull;  such drugs are typically given in doses under 20 mg per day not doses under 20 mg (0.00071 oz) per day (topic area in which conversion is of little value to the reader)
 * In text dense with measurements, conversion of every measurement may add clutter to little benefit. In such cases editorial judgment will dictate which, if any, measurements should carry conversions:
 * &bull;  Popular model gauges range from 6.5 mm (​0.256 in) to 45 mm (1.77 in).
 * Popular model gauges are 6.5 mm (​0.256 in), 9 mm, 12 mm, 16.5 mm, 25 mm, 30 mm, and 45 mm (1.77 in).
 * Certain topic areas may benefit from a mixed approach e.g. American football:
 * &bull;  Games are played on a rectangular field 120 yards (110 m) long and 53.33 yards (48.76 m) wide, with goal lines are marked 10 yards (9.1 m) inward from each end...
 * Note: This article discusses movements of players and the ball in units of yards (0.91 m), as is standard in the sport.
 * The offense is given a series of four plays, known as downs. If the offense advances ten or more yards in the four downs, they are awarded a new set of four downs. If they fail to advance ten yards, possession of the football is turned over to the defense... On a kickoff, the ball is placed at the 35-yard line of the kicking team in professional and college play and at the 40-yard line in high school play.


 * In some cases, it may be helpful to provide a sense of scale instead of a conventional conversion:
 * &bull;  a giant star of radius 61 million kilometres (44 times that of the sun)
 * &bull;  diameter as small as 14 nm (about 63 silicon-atom diameters)
 * &bull;  precise assays are possible on samples as small as 0.1 ml (about the size of a pinhead) (Note that a source may be needed for such comparisons, if not allowable under WP:CALC.)
 * Where an imperial unit is not part of [etc etc]

 E Eng  20:17, 22 May 2016 (UTC)
 * It's getting a bit like the old joke about economics (how do you get four theories on economics? Put three economists in a room together!). Seriously though, Proposal A5 has merit. I'm going to sleep on it, maybe not even look at it for a couple of days, go write some articles only involving metre/feet conversions, and come back and take another look. The football idea has legs (around 40 if you only include onfield players and officials, more if you include coaches, cheerleaders etc). Robevans123 (talk) 21:03, 22 May 2016 (UTC)
 * The president of Harvard is meeting with the chairman of the physics department. "You physicists!", he exclaims. "Why do you need all this expensive equipment? Look at the math department—‌all they ask me for is paper, pencils, and erasers.


 * "And the [insert favorite department name here – economics, psychology, philosophy] department—‌they don't even want erasers!"
 *  E Eng  01:18, 23 May 2016 (UTC)
 * I'll just add here that I'm in favour of any proposal that makes exclusion of conversions the exception rather than the rule, I don't have much to say about the exact details, but what I see here looks good. FunkMonk (talk) 21:55, 22 May 2016 (UTC)
 * No doubt comments from others will help improve this even more.  E Eng  01:18, 23 May 2016 (UTC)

I'd quibble some of the examples given. I find it rather more interesting and instructive that the radius of the giant star is about 0.41 Astronomical units (otherwise put, 41% of the mean Earth-Sun distance) than that it's 44 solar radii, and I wonder how many people are going to find it useful to learn that 14 nanometres is the diameter of 63 silicon atoms. In context, sure, it may be appropriate, but if it's a context-specific choice we need to give the context in the guideline. Overall though, the reason I haven't got involved before now is that I'm broadly happy with the way this is going.

I can also see some people might start getting hung up on double decker buses, or areas the size of Wales. Kahastok talk 20:09, 23 May 2016 (UTC)
 * Um, I'm finding that last bit about the buses and so a bit obscure.  E Eng  15:13, 25 May 2016 (UTC)

Proposal A6
Taking 's comments on board, and putting the football example on a further diet...


 * Where English-speaking countries use different units for the same quantity, the "primary" quantity should usually be followed by a conversion in parentheses: the Mississippi River is 2320 mi long; the Murray River is 2508 km long.
 * However, in some circumstances conversion is inappropriate:
 * &bull;  such drugs are typically given in doses under 20 mg not under 20 mg (0.00071 oz) (topic area in which conversion is of little value to the reader)
 * In text dense with measurements, conversion of every measurement may add clutter to little benefit. In such cases editorial judgment will dictate which, if any, measurements should carry conversions:
 * &bull;  Popular gauges are 6.5 mm (​0.256 in), 30 mm (1.18 in), and 45 mm (1.77 in).
 * Popular gauges are 6.5 mm (​0.256 in), 9 mm, 12 mm, 16.5 mm, 20 mm, 25 mm, 30 mm, and 45 mm (1.77 in).
 * Certain topic areas may benefit from a mixed approach e.g. American football:
 * &bull;  Games are played on a rectangular field 120 yards (110 m) long and $53 1/3$ yards (48.8 m) wide, with goal lines are marked 10 yards (9.1 m) inward from each end...
 * Note: This section discusses movements of the ball in units of yards (0.91 m), as is standard in the sport. On a kickoff, the ball is placed at the 35-yard line of the kicking team (the 40-yard line in high school play). If the offense advances ten or more yards in the four plays, they are awarded a new set of four plays. If they fail to advance ten yards, the ball is turned over to the defense...
 * In some cases, it may be helpful to provide a sense of scale instead of a conventional conversion:
 * &bull;  a giant star of radius 61 million kilometres (44 times that of the sun) or a giant star of radius of 61 million kilometres (41% of the mean Earth-Sun distance)
 * &bull;  fabrication of semiconductor devices as small as 14 nm (about 63 silicon-atom diameters)
 * &bull;  precise assays are possible on samples as small as 0.1 ml (about the size of a pinhead) (Note that a source may be needed for such comparisons, if not allowable under WP:CALC.)
 * Where an imperial unit is not part of [etc etc]

 E Eng  05:41, 25 May 2016 (UTC)


 * This is looking really good. I'm going to nit-pick like mad so that maybe the final step on this journey is Edinburgh to Carlisle (A7)...
 * Intro sentence:
 * Where English-speaking countries use different units for the same quantity, the "primary" quantity should usually be followed by a conversion in parentheses, for example: the Mississippi River is 2320 mi long, or (from Australia) the Murray River is 2508 km long.
 * Rationale: This lead has always bugged me - the semi-colon in black is really hard to spot so it looks like the two examples are from one article.
 * Drug example:
 * WorldMegaPharma had to withdraw the blister packs of 20 mg tablets not 20 mg (0.00071 oz) (topic area in which conversion is of little value to the reader and drug dosages are now widely given in mg)
 * Rationale: While originally researching this conversion I found that WikiProject Pharmacology avoids giving dosages except in general discussions (Medical disclaimer), and the US press regularly uses mg without conversions.
 * Model scale example: - Perfick!
 * American football example: - just a small copy edit - ...with goal lines are marked...
 * Sense of scale:
 * In some cases, it may be helpful to provide a sense of scale in addition to, or instead of, a conventional conversion:
 * Rationale: Where common units are used, for example, kilometres, but with a very large value, then it's still useful to include a metric/US customary conversion as well, for example, a giant star of radius 61 million kilometres (38 million miles, or 44 times that of the sun) - don't know if the convert template can cope with this... The small scale examples are absolutely appropriate for the context.
 * And finally, I think was warning on using unusual units such as:
 * The asteroid's largest crater is about the size of Wales. Do not use conversions that may be confusing or unknown to the lay reader.
 * Rationale: Although this and other unusual units may be meaningful to regional audiences they may not play in Peoria, just as "The asteroid's largest crater is about 6.5 times the size of Rhode Island" wouldn't play in Pontypool.
 * Robevans123 (talk) 19:52, 25 May 2016 (UTC)

Proposal A7
Integrating Robevans123's excellent nitpicks, though with a different solution for the river-semicolon problem, and various other adjustments -- anyone, feel free to adjust/change in place, as long as doing so doesn't make any comments already made hard to understand. (Later: also integrating Robevans123's later material on the giant star example.)


 * Where English-speaking countries use different units for the same quantity, the "primary" quantity should usually be followed by a conversion in parentheses:
 * &bull;  the Mississippi River is 2320 mi long (American topic)
 * &bull;  the Murray River is 2508 km long (Australian topic)
 * However, in some circumstances conversion is inappropriate:
 * &bull;  United Consolidated Amalgamated Intergalactic GigaPharma Ltd. withdrew its 20 mg tablets not its 20 mg (0.00071 oz) tablets (topic area in which conversion is of little value to the reader)
 * In text dense with measurements, conversion of every measurement may add clutter to little benefit. In such cases judgment will dictate which, if any, measurements should carry conversions:
 * &bull;  Popular gauges are 6.5 mm (​0.256 in), 30 mm (1.18 in), and 45 mm (1.77 in).
 * Popular gauges are 6.5 mm (​0.256 in), 9 mm, 12 mm, 16.5 mm, 20 mm, 25 mm, 30 mm, and 45 mm (1.77 in).
 * Certain topics may benefit from a mixed approach e.g. American football:
 * &bull;  Games are played on a rectangular field 120 yards (110 m) long and $53 1/3$ yards (48.8 m) wide, with goal lines marked 10 yards (9.1 m) inward from each end...
 * Note: This section discusses movements of the ball in units of yards (0.91 m), as is standard in the sport. On a kickoff, the ball is placed at the 35-yard line of the kicking team (the 40-yard line in high school play). If the offense advances ten or more yards in the four plays, they are awarded a new set of four plays. If they fail to advance ten yards, the ball is turned over to the defense...
 * In some cases, it may be helpful to provide a sense of scale instead of, or in addition to, a conventional conversion (though a source may be needed for such comparisons, if not allowable under WP:CALC):
 * &bull;  fabrication of semiconductor devices as small as 14 nm (about 63 silicon-atom diameters)
 * &bull;  precise assays are possible on samples as small as 0.1 ml (about the size of a pinhead)
 * &bull;  a giant star of radius 257 million kilometres (160 million miles, about 370 times the radius of the sun and 1.72 times the mean Earth-Sun distance)
 * &bull;  Ash covered some 170,000 km2 (66,000 mi2, or about the area of Florida) (Scale comparisons should have concrete meaning for most English-speaking readers, and should not be the closest match from an arbitrary list of candidates.)
 * Where an imperial unit is not part of [etc etc]
 * Where an imperial unit is not part of [etc etc]

The "large list of candidates" wording needs work. (I needed to switch to Florida from Wales to make the "list of candidates" point.) On the giant star, we now have three conversions in the mix -- miles, radius of the sun, au. I think two is the max, and here I've used miles and au; but personally I wonder if radius-of-sun and au wouldn't be better.  E Eng  05:21, 26 May 2016 (UTC)


 * Was looking at the giant star example and writing an alternative, and then edit-conflicted, but this is what I had:


 * can sometimes cope with three units (useful when you've got different US/Imperial units that are different but doesn't work for kilometres), but agree that it's not ideal and can be a bit cluttered. I found this description of star size units (in an article, not a style guide...), but it does seem to be sensible and matches some giant star examples.
 * Taking an example from R Doradus (a red giant) The estimated diameter of R Doradus is 515 ± 70 million km (3.46 AU) or 370 ± 50 times the diameter of the Sun. but gives the radius as 370 ± 50 R☉ in the infobox (only R☉, solar radius, is wikilinked to a definition).
 * There a few problems with this in that although AU (astronomical unit) is purely a measure of length it is based on a radius (mean Earth-Sun distance) so it's a bit like comparing the diameter of a basketball ball with the radius of a baseball ball. Also R☉ and AU are not particularly common units unless you an astronomer. I think I'd favour a statement like:
 * The estimated radius of R Doradus is about 370 R☉ (solar radius), or 1.72 astronomical units.
 * Or possibly, adding a sense of scale, something like:
 * The estimated radius of R Doradus is about 370 R☉ (solar radius), or 1.72 astronomical units (mean Earth-Sun distance), which is about 257 million kilometres (160 million miles).
 * Which also gives a good idea that if we were going around R Doradus we'd be fried!
 * BTW - happy with the tweaks that EEng has done to the rest of the proposal. Definitely better splitting the American/Australian examples into bullets.
 * I think the conversions are ok - will check them again though. For the sake of clarity I've ignored the ± variations.
 * Robevans123 (talk) 22:47, 26 May 2016 (UTC)
 * Stellar conversion examples are all correct now.
 * doesn't support R☉ (solar radius) - will put in request for that. Robevans123 (talk) 23:48, 26 May 2016 (UTC)


 * My blood sugar is a bit low, but I took your last version re giant star and (jiggling it around a bit) integrated it into A7. I couldn't find a way to use the R☉ symbolism and keep the wording natural. As always feel free to modify in place so long as that doesn't make comments already made hard to interpret. Also, though I left in the miles conversion for the star, I think it's an interesting question whether it's necessary. Even the unmetricated know that a shitload of kilometers is also a shitload of miles, and I wonder whether giving the actual size of the miles shitload tells them much, especially given the presence of the scale comparisons.


 * Where is everybody???  E Eng ' 00:40, 27 May 2016 (UTC)


 * I think the stellar example is now fine (it was trying to do too much with conversions and a quick intro to the units at the same time), especially as the article just gives that sort of distance once. I looked at main sequence, which describes one of it's main units (solar mass, M☉) fairly well, and then just uses it. Interestingly, it doesn't offer any equivalent or comparable masses, and for the life of me, I can't think of any (cars 1-2 tonnes, locomotives 50-100 tonnes, large aircraft ~500 tonnes, aircraft carrier ~80,000 tonnes, and then there's a massive leap up to earth's mass ~6 x 1021 tonnes)
 * I think it's better to leave the miles in - if it's worth stating in kilometres then it's worth stating in miles. Having been interested in astronomy from the age of 9 I have had 93 million miles as the mean Earth-Sun distance in my mind for 50 years (you do the math(s))..., but I accept that it's really difficult to work out what will be useful to readers with different backgrounds.
 * I do think it is important that we introduce an element of exactitude to shitloads though. We could start off with MegaShitloads, KiloShitloads, Shitloads, MilliShitloads, and MicroShitloads, and see if that's enough... Robevans123 (talk) 09:39, 27 May 2016 (UTC)


 * I have arrived somewhat late to this discussion, at a stage when it's already ballooned to the point of being hard to follow. I have one pedantic comment here: it's not obvious why you'd ever want to convert milligrams to a fairly meaningless decimal-dust-laden number of avoirdupois ounces – if it was desirable to provide an "old money" equivalent for such a prescription then it would be in apothecary units, something like 20 mg. This is not the sort of thing the MOS needs to have a rule about. But in any such case, providing a conversion is surplus to requirements, I think, since the "old money" there is quite deprecated.


 * By an extension of this argument, I don't particularly see the point in converting stuff in science articles at all since it's not representative of standard scientific practice (and it is such standard practice which the MOS is supposed to be based on). A reputable scientific source would not detail the LHC in anything other than SI units (and "friends" such as the electronvolt); converting the length to miles and furlongs and whatnot, or the temperature to Fahrenheit or Rankine or other obsolete scales, or converting the energy stored in the ATLAS magnetic field to pound-feet, is excessive and it does not really provide additional useful information. Whatever the primary unit (in WP or real life), an SI equivalent should always be provided, but I do not think the "old money" should be used at all outside of contexts where it has not yet been deprecated. Archon 2488 (talk) 10:54, 27 May 2016 (UTC)
 * "since it's not representative of standard scientific practice" Wikipedia is not a science journal, our target audience is mainly lay readers. As copied from the Pharmacy project guidelines earlier: "Finally it is important to keep in mind that we are writing a general encyclopedia, intended to be read by the lay public so it is important to make technical material as accessible as possible to a wide audience but at the same time, not reducing the value of the article to more technical readers including medical doctors, pharmacists, and scientists." Adding conversions is win-win, it is not as if we are reducing the value for anyone. FunkMonk (talk) 11:00, 27 May 2016 (UTC)
 * "our target audience is mainly lay readers" is true in broad outline, perhaps, but I doubt many lay people want to read about Fermi's golden rule. I have no idea how you would even format such an article for a lay audience, or whether it would be desirable to do so. In its science articles, I'd argue that WP already de facto follows scientific conventions for most things (including, for example, using standard technical terminology without excessive glossing).


 * My point is that excessive conversions are comparable to such excessive glossing. If someone reading an article about zoology is not expected to need terms like "mammal" to be glossed (certainly not on every occurrence) then I don't see why terms like "centimetres" need to be de facto glossed by a convert template. It's fine to argue that it doesn't detract – adding stuff doesn't detract, sure, but it clutters things unnecessarily. Converting light wavelengths in nanometres to microinches (!) would be one such excessive addition – a unit which would almost never see use in any real-world reputable source from this side of the 1970s, certainly. Fact is, in scientific contexts, measuring temperatures in Fahrenheit is almost unheard of, and one might argue that mandating its use would be incompatible with WP:NPOV. So it's not as simple as "win-win"; there is a necessary discussion about when such conversions are useful at all, and when they are excessive.


 * My standard rule would be: if there is some real-world reason, in line with NPOV, why some non-SI unit would be relevant, then it may be provided in brackets, but otherwise the style guidance should be to omit it. For example, it might be desirable to point out that the reason why a gamma camera scintillator crystal has a rather odd thickness of 9.525 mm is that it was historically $3/8$ inch, but this would not be a reason to convert all millimetres to inches in such an article. Archon 2488 (talk) 11:20, 27 May 2016 (UTC)
 * I think the point here is mostly geared at the question, what is science? I think the balance here is correct, but I don't think we're coming at this from massively different directions.  Because I think a lot of the concerns you express are already addressed by the proposed guideline.  We start this proposal by saying:


 * Where English-speaking countries use different units for the same quantity, the "primary" quantity should usually be followed by a conversion in parentheses...


 * and we say something similar in the standing version of the guideline. Clearly, if English-speaking countries use the same unit, this doesn't apply.  It also makes it clear that in topic areas "in which conversion is of little value to the reader", "conversion is inappropriate".  I find it difficult to see how hard science - including your examples of the wavelength of light or the thickness of a gamma camera scintillator crystal - would not clearly be excluded from conversions by these two rules.  Everyone uses the same units and conversion is of little value to the reader.


 * But there are areas where science meets more general interest. These areas where there is likely to be a genuine difference between lay readers in different countries and I see no reason not to give both versions where it does not detract from what we say.  For example, when it comes to the length of an animal, it seems odd and unnecessary to refuse to provide conversions.  And I think this proposal provides a number of good examples of where it may detract or be unnecessary to provide conversions and where it is likely to be desirable. Kahastok talk 17:28, 27 May 2016 (UTC)


 * It is interesting that Archon and I noticed the same thing, but I strongly object to the 20mg to ounces conversion. That would never have been used, as one would've likely used grains for that purpose. Of course, the grain conversion is absolutely useless to our readers, so I'd say that it provides a good example of when not to use a conversion. Scrap ounces, put in grains. RGloucester  — ☎ 15:40, 27 May 2016 (UTC)

An interlude

 * Um, "I strongly object to the 20mg to ounces conversion" -- huh? The drug example says not to make that conversion.
 * The current guideline says,
 * Where English-speaking countries use different units for the same quantity, follow the "primary" quantity with a conversion in parentheses
 * A7 weakens this substantially:
 * Where English-speaking countries use different units for the same quantity, the "primary" quantity should usually be followed by a conversion in parentheses
 * This is a substantial movement toward "conversion's optional", so I'm not sure why some people are worried that conversions will be popping up in inappropriate places. Nonetheless let me suggest this alternative, which implies conversion as the default, while still making very clear that not converting may be perfectly fine as well:
 * Where English-speaking countries use different units for the same quantity, the "primary" quantity will typically be followed by a conversion in parentheses


 * Finally, I'd like to change the inappropriate-to-convert section to this (updated per RGloucester, below):
 * ''However, in some circumstances secondary units are unknown or obsolete in the topic area, and of little or no value to the reader:
 * &bull;  United Consolidated Amalgamated Intergalactic GigaPharma Ltd. withdrew its 100 mg tablets not its 100 mg (0.00353 oz) tablets nor its 100 mg (1.54 grain) tablets
 * &bull;  Visible light is usually defined as having wavelengths in the 400–700 nm range not the 400–700 nm (14.75–27.56 &mu;in) range

Would this help?  E Eng  04:20, 28 May 2016 (UTC)
 * I was simply saying that an mg to oz conversion is a bad example because it doesn't make any sense, as the two units are not equivalent in use. The equivalent would've been grains, not ounces, as I'm sure you've figured out. A grain conversion, while correct, would be "of little or no value to reader", as the grain is no longer used. On the other hand, the ounce was never used for measuring a tablet of some drug, and usage in this instance is simply wrong. Do you understand the distinction, i.e. between a correct but disused conversion and a nonsense conversion? RGloucester  — ☎ 04:32, 28 May 2016 (UTC)
 * Sorry, I was using my mouse-brain by mistake. I've modified the example above. I'm assuming you have an abacus that works in grains so please check my math.  E Eng  09:09, 28 May 2016 (UTC)
 * The convert template does actually support grains, as I showed above. So 100 mg or 100 mg (the latter probably makes more sense when using Ye Kynge's Moste Olde Measures, but to press that point would be rather like arguing about the gender of the angels since these units are so totally deprecated). Also, I don't think that the ersatz symbol "&mu;in" is permitted by the MOS in any case. Convert just gives it in scientific notation: 400 - 700 nm. Another pedantic niggle here: the first part of your conversion to microinches seems to be wrong: should be 15.75 rather than 14.75. My advice would just be to put these in via the convert template since that is how they'd likely manifest in an article, should someone try to add them.


 * (A discussion for another day would be why convert supports deprecated units like the grain that we are in effect telling people not to use – in those incredibly rare cases where you had, say, a quantity defined in grains, you could just do the conversion manually. One might argue that putting in unnecessary units might just encourage people to use them without justification, hence leading to the kind of unit proliferation we're trying to avoid.) Archon 2488 (talk) 13:27, 28 May 2016 (UTC)
 * The one article where I know that the grain appears in is aspirin. RGloucester  — ☎ 15:07, 28 May 2016 (UTC)
 * The idea of restricting template interfaces to coerce MOS compliance comes up a lot in the context of cite and so on. I think it's a bad idea. It's a bit paternalistic, and you can certainly imagine situations (e.g. a discussion of the history of pharmacy) where it's somehow needed.  E Eng  15:36, 28 May 2016 (UTC)
 * The aspirin article was the only drug-related article I could find that included a grain conversion, and in that particular usage the conversion to grains is entirely reasonable - as it's explaining the history of the size of aspirin doses. As I've mentioned elsewhere the WikiProject Pharmocology style guide deprecates details on dosages generally, but allows it in general discussions (this is what prompted the example of a drug being recalled, based on a real article). I think the drug example stands as an example of both a nonsense conversion (where it could be regarded as an attempt to put the value into imperial/US customary units, in an area where people everywhere probably think of drug doses in mg), and also an example of a conversion into an effectively obsolete unit (in the context of drug doses where even the US would appear to be fully metricated), but see later note on obsolete/deprecated units below. BTW if you look at the description photo (from 2007) of an aspirin bottle used in the article, the contributor claims the image shows that common dosage is 5 grains (325 mg) when the label actually reads 325 mg (5gr) - looks like a last stand against metrication of drugs in the US!
 * While googling around on the subject of grains and drugs I did notice that the recreational drugs market is not fully metricated yet! This useful source shows 24 uses of US customary units, 13 metric units, and two unusual units (brick and half a football field)!-;)
 * Also, we need to be careful about classifying a unit as deprecated as opposed to obsolete. A unit may be deprecated in some areas, but it may well still be in common usage. For example, the Guide for the Use of the International System of Units (SI), published by NIST, deprecates ppm, ppb, and ppt, but recognises that these may be required by a law or a regulation (page 30). And I note that ppm is used in a number of scientific articles (for example Proton nuclear magnetic resonance, which is a good example of why we shouldn't adopt style guides from external agencies (although they can be a useful source of information on units).
 * BTW the grain is still the standard unit for the weight of bullets (there are hundreds of pages that describe bullets and give the weight in grains), so it could not even be described as an obsolete unit...Robevans123 (talk) 17:27, 28 May 2016 (UTC)
 * Let's put in a request for convert to handle keys of cocaine, tabs of acid, lids/dime bags of pot, and so on.  E Eng  17:56, 28 May 2016 (UTC)
 * A good idea. You'd also need to provide data on the tolerance of weights etc, and also assay values on the quality, as I understand these values are rather less precise than the values you might expect in science articles. Robevans123 (talk) 18:07, 28 May 2016 (UTC)


 * Except for science-based articles, which can use international units alone, conversions should on no account be optional—especially international units after a British Empire unit. Tony   (talk)  15:37, 28 May 2016 (UTC)
 * Do you really mean that? So in Super_Bowl_XIX you want all that talk of who had how many rushing yards (or whathaveyou) --
 * San Francisco defensive back Dana McLemore returned the ball 28 yards to the 49ers 45-yard line. After advancing 15 yards with two running plays, Montana completed a pair of passes to tight end Russ Francis to move the ball 29 yards to the Miami 11-yard line.
 * converted into meters? E Eng ''' 16:10, 28 May 2016 (UTC)
 * User:Tony1 - can you provide examples of scientific articles where the conversion of some units, at least to give a sense of scale, would be detrimental to the article? As noted, the american football example is a good example of where you might only convert a unit on first use, and then stick to primary unit, and this might apply equally where the primary unit is US customary/imperial or metric. Robevans123 (talk) 17:27, 28 May 2016 (UTC)
 * More pedantic comments on my part: "conversion" and "sense of scale" are different. Converting the mass of an asteroid from kilograms to pounds or stones or hundredweights is pointless; relating its mass to that of the moon or the earth might provide a useful sense of scale. This is what is done, for example, in the article on Ceres. I am wary of introducing any phrasing that might endorse routine conversion of SI to imperial in the context of science-related articles. For that reason, I also would dispute the wisdom of asking "is there any example of when conversions are detrimental?". What we're trying to do here is put a brake on excessive conversions in science articles, so I'd argue that that is not the angle from which we want to approach things. Similarly, WP does not accept "there is no detriment to having an article on this" as an argument not to delete an article. Simply because we can put something there doesn't mean we ought to.


 * I would argue that there are extremely few cases where it would be desirable or even permissible to have an article in imperial or USC without conversion. The use of yards in American football is used as almost the sole example, for a good reason. It is a topic which is almost exclusively of interest to Americans, and it uses USC units exclusively. Therefore a deviation from the normal requirement for an explicit SI conversion every time is permitted. But I doubt there are many other topics where these conditions are met. Archon 2488 (talk) 19:07, 28 May 2016 (UTC)


 * Yes, I think "is there any example of when conversions are detrimental?" is a good question, and yes, I think there are good examples where it will be, such as the wavelength of light in the proposed change.


 * If we're allowed to use SI without conversion then it stands to reason that where similar circumstances arise with non-SI unit we should be allowed to use those non-SI units without conversion. It seems bizarre to insist on conversions no matter what in one direction, and not to similarly insist on conversions the other way.  That is not, of course, to say that these circumstances will be as common with imperial or US customary units as they are in SI.


 * FWIW, another example is maritime law, yet another might be height of aircraft. In topics dense with these measurements, you wouldn't want to convert every measurement.  And of course SI does not formally accept any time period longer than a day, but we're never going to have articles that routinely provide conversions into seconds (or even Megaseconds or Gigaseconds). Kahastok talk 19:39, 28 May 2016 (UTC)


 * They're not symmetric situations (imperial/USC to SI and vice versa), for a couple of reasons. Firstly, the legacy units have no existence independent of SI; one cannot even speak of "inches" without implicitly invoking SI standards, whereas the converse is obviously false. Secondly, SI is an international standard, and the normal system in use on WP, and the normal system of units in use in virtually every country on Earth, whereas the old money is decidedly none of those things.


 * For aviation altitudes, one typically encounters a mixture of feet and metres in sources (since in most countries feet are archaic and deprecated outside of this single context). Moreover, for comparison with terrain elevations (normally in metres in every country except the USA, I think), and to speak to people under retirement age in a language they understand, a conversion to metres is useful. Similarly, nautical miles are a "jargon" unit, like the AU, which should be converted since they are of little direct meaning to most people. If I'm confronted with a number of nautical miles I just double it in my head to get a rough number of kilometres, for example.


 * I don't know why SI doesn't accept the week if it accepts minutes, hours, and days, but the (calendar) month and year are obviously not of consistent length, so I assume that is the reason. In any case, I think there is little chance that megaseconds or gigaseconds will be used in articles, so I don't find this especially relevant. Archon 2488 (talk) 20:05, 28 May 2016 (UTC)


 * I don't think anyone who's been in these discussions does not know that you prefer metric measures. Your preference does not override the likely preferences of a large proportion of our readers.  Do you  really think people in the US retire before they finish school?


 * Yes, it's helpful to convert in most cases, but if you're describing air manoeuvres in detail - particularly in a place where land elevation is not significant - you're probably not going to want to put a conversion on every single altitude, which is what you seem to be proposing. Similarly nautical miles in maritime law.  Similarly yards in American football as in the proposal.  In the case of the non-SI light year and parsec - that's a clear scientific context - you're unlikely to want to convert to SI units at all.  You say the year is irrelevant and you airily dismiss the Gigasecond and Megasecond, but if there always has to be a conversion to SI they have to be there.


 * Where English-speaking countries all use the same non-SI measure, where the SI measures are unknown or obsolete, where imperial-first text is dense with measurements, and in all the other circumstances we allow unconverted SI units, it seems bizarre not to allow the unconverted non-SI unit equivalently. And I must admit I can't for the life of me see how that could be controversial: the idea that we should feel the need always to have a conversion to SI for every non-SI unit, no matter how well used the SI and non-SI units are, no matter whether the SI units are relevant, no matter what all those conversions do to the article, is frankly absurd.  Kahastok talk 21:08, 28 May 2016 (UTC)


 * There's a certain amount of misrepresentation going on there. Firstly, we're not talking at all about US-related non-science articles (or at least I wasn't) and we're now getting quite off-topic. Secondly, we're not talking about my personal preferences (or at least I wasn't, so thanks for trying to derail the discussion onto that topic).


 * Given that WP always converts miles to kilometres in US articles, I do not accept that feet in aviation or nautical miles are any different.


 * I did not say years were "irrelevant" (that is your word, not mine, and I do not accept it as a paraphrase of my argument); I said that because a year is not a unit of consistent length, that is probably why it is not listed as a unit in the SI brochure. I did not "airily dismiss" megaseconds and gigaseconds (and I don't understand why you think those unit names need to be capitalised). I observed that there is no practical reason why such units would be used on WP, and I do not think MOS discussions should revolve around scenarios which do not occur in practice. Absent some real dispute in article-space about the merits of years versus gigaseconds, there is no purpose in discussing the topic at the level of MOSNUM. In this sense, only, my position could be stated as "years versus gigaseconds is an irrelevant dispute". Please stop misrepresenting me.


 * In relation to some of the other points you raise: firstly, I don't know of any instances where an SI unit is "obsolete"; SI was designed to replace older systems of measurement, so that doesn't really make sense. It's sort of like saying that horse-drawn carriages might one day deprecate battery-electric autonomous vehicles. Policies on when to provide specific conversions might be better decided at the topic/project level (e.g. American football) than the MOS level, however. I was not arguing that the MOS should require an absence of conversions; that is too paternalistic, to use EEng's word. In practice, if editors protest the lack of conversions, then in most cases they will be added. Archon 2488 (talk) 21:53, 28 May 2016 (UTC)
 * I think we should be careful about making comments like a certain amount of misrepresentation going on there. Probably best to just correct and/or clarify. If not, I'll start making comments on fallacious arguments like or the temperature to Fahrenheit or Rankine or other obsolete scales, which is classic example of False equivalence, as although Rankine is a pretty much forgotten obsolete scale, Fahrenheit is the most commonly used temperature scale in the US, and still survives to a lesser extent in countries that have been metricated or semi-metricated. Of course it may just be that the editor was just not aware of the use of Fahrenheit, in which case I apologise, or it could have just been a cheap debating trick. But it's probably best to let the participants make their own judgements... -;) Robevans123 (talk) 22:40, 28 May 2016 (UTC)
 * Clarification: in this context we are talking specifically about science articles, not (for example) how one would report the weather in the US. Rankine is still used, in fact, in some US engineering applications. However, I would not expect a paper in the New England Journal of Medicine to describe human body temperatures in anything other than degrees Celsius (for example). In the context in which my comments were made, they were not a false equivalence or a misrepresentation. Archon 2488 (talk) 23:21, 28 May 2016 (UTC)
 * Fair enough - gone back and read in detail - my bad. Sorry - only just noticed your edit above.Robevans123 (talk) 15:08, 29 May 2016 (UTC)
 * And yet you are arguing for a difference in treatment. We should always convert non-SI to SI, but not vice versa, even if equivalent situations arise.  This is a daft idea.  You dismiss the time point again, but fail to rebut it.  A time period of 100 years is not SI.  If all non-SI units must be accompanied by a conversion into SI then that cannot not include a period measured in years.  Are you proposing to convert 100 years to 36.5 kilodays instead?  877 kilohours?


 * I think that when the same circumstances arise, the same outcome should result, whether the primary unit is SI or non-SI. Just as we do not convert SI when all the English-speaking world use SI, so we do not convert a non-SI unit when it is used by all the English-speaking world.  Just as we do not convert into non-SI units unknown or obsolete in the topic area that are of little or no value to the reader, so we do not convert into SI units unknown or obsolete in the topic area that are of little or no value to the reader.  Just as in texts dense with measurements we do not convert every single measurement into non-SI units, so in texts dense with measurements we do not convert every single measurement into SI units.  Try as I might, I still can't see how that concept could be in any way controversial.


 * (And the fact that SI was designed to replace older systems of measurements does not mean that its units cannot be obsolete. The cgs system was also designed to replace older systems of measurement - does that mean that the erg, the dyne and the gal are not obsolete?  But that's beside the point.) Kahastok talk 22:26, 28 May 2016 (UTC)


 * (ec) SI units will not be obsolete until and unless a replacement for SI is devised, at some hypothetical point in the future. Until that happens, there is no merit in entertaining such an idea here. This is another argument which is not based on a realistic scenario.


 * In the case of time, you're arguing against a position which nobody is advocating (that I can tell). This is the definition of a strawman. To clarify: I am not arguing that we should replace litres with cubic decimetres simply because the latter is SI and the former is not. I have told you several times before that I am not arguing for kilodays or kilohours, and I find it somewhat obnoxious and tedious that you keep bringing it up. Given that you are literally the only person who seems to have a problem with this, you can safely assume that it will never be a problem in the real world.


 * (And, please, "daft" and "bizarre" do not belong in a constructive discussion. If you're gonna accuse other people of "airily dismissing" others' opinions, don't do it yourself.) Archon 2488 (talk) 23:21, 28 May 2016 (UTC)


 * To focus discussion, I suggest that people please crystallize any concerns they have in terms of specific text from A8 which they're concerned about, or in terms of specific suggested changes/additions. Please do that in the A8 section (below).'  E Eng  23:12, 28 May 2016 (UTC)

Proposal A8
Here's A8, based on all the above ( and later extended/modified as detailed in the collapse section below ):
 * Apparently &mu;in is legit
 * I've switched the grains to fractions to make it more quaint
 * Note the new phrasings the "primary" quantity will typically and in some circumstances secondary units are unknown or obsolete in the topic area


 * Where English-speaking countries use different units for the same quantity, the "primary" quantity will typically be followed by a conversion in parentheses. Generally, conversions to and from metric units and US or imperial units should be provided:
 * &bull;  the Mississippi River is 2320 mi long (American topic)
 * &bull;  the Murray River is 2508 km long (Australian topic)
 * However, do not convert where it would make a common or linked expression awkward (The four-minute mile).
 * ''In some circumstances secondary units are unknown or obsolete in the topic area, and of little or no value to the reader:
 * &bull;  United Consolidated Amalgamated Intergalactic GigaPharma Ltd. withdrew its 100 mg tablets not  its 100 mg tablets and definitely not its 100 mg (0.00353 oz) tablets
 * &bull;  Visible light is usually defined as having wavelengths in the 400–700 nm range not the 400–700 nm (15.8–27.6 × 10-6 in) range
 * In text dense with measurements, conversion of every measurement may add clutter to little benefit. In such cases judgment will dictate which, if any, measurements should carry conversions:
 * &bull;  Popular gauges are 6.5 mm (​0.256 in), 30 mm (1.18 in), and 45 mm (1.77 in).
 * Popular gauges are 6.5 mm (​0.256 in), 9 mm, 12 mm, 16.5 mm, 20 mm, 25 mm, 30 mm, and 45 mm (1.77 in).
 * Certain topics may benefit from a mixed approach e.g. American football:
 * &bull;  The field is rectangular, 120 yards (110 m) long and $53 1/3$ yards (48.8 m) wide, with goal lines marked 10 yards (9.1 m) inward from each end...
 * Note: This section discusses movements of the ball in units of yards (0.91 m), as is standard in the sport. On a kickoff, the ball is placed at the 35-yard line of the kicking team (the 40-yard line in high school play). If the offense advances ten or more yards in the four plays, they are awarded a new set of four plays. If they fail to advance ten yards, the ball is turned over to the defense...
 * Where an imperial unit is not part of the US customary system, or vice-versa – and in particular, where those systems give a single term different definitions – a double conversion may be appropriate: Rosie weighed 80 kg (markup: ); The car had a fuel economy of 5 L/100km (markup:  ).
 * In some cases, it may be helpful to provide a sense of scale instead of, or in addition to, a conventional conversion (though a source may be needed for such comparisons, if not allowable under WP:CALC):
 * &bull;  fabrication of semiconductor devices as small as 14 nm (about 63 silicon-atom diameters)
 * &bull;  precise assays are possible on samples as small as 0.1 ml (about the size of a pinhead)
 * &bull;  a giant star of radius 257 million kilometres (160 million miles, about 370 times the radius of the sun and 1.72 times the mean Earth-Sun distance)
 * &bull;  Ash covered some 170,000 km2 (66,000 sq mi, or about the area of Florida) (Scale comparisons should have concrete meaning for most English-speaking readers, and should not be the closest match from an arbitrary list of candidates.)
 * Converted quantity values should use a level of precision similar [etc etc]
 * Converted quantity values should use a level of precision similar [etc etc]

 E Eng  15:36, 28 May 2016 (UTC)


 * I'm confused by the word "legit" here – the fact that you can find a source that uses that notation does not, by itself, prove anything. As far as I can tell, MOSNUM does not presently allow the use of SI prefixes with imperial/USC units (unlike with SI, there are no universally accepted standards for the use of the old units, so every field, and potentially every author, can adopt their own convention). So a notation like "&mu;in" would be impermissible on Wikipedia in any case. The ambiguity here is that the current phrasing suggests such notations would ever be acceptable, rather than simply saying that they are redundant in this case. Similarly, the made-up symbol "mi2" is AFAIK not supposed to be used on WP.


 * It's maybe beyond the scope of this discussion, but I firmly oppose the use of SI prefixes with non-metric units, since this is likely to cause confusion. If for some reason people want to convert distances in the solar system to miles, made-up symbols like "Mmi" and "Gmi" should not be used. If there is any confusion over this point, we should discuss and add an entry to the "Prefixes" section of the relevant MOSNUM table. Archon 2488 (talk) 17:20, 28 May 2016 (UTC)
 * If you prefer "microinches" over &mu;in then you could have just edited A8, as I'm doing here, with an edit summary indicating that you think &mu;in is a bad idea. No need for everything to be laboriously talked out here -- be bold.
 * The other stuff really is out of scope here. I'd really consider it a favor if you could say what you think about A8 overall
 *  E Eng  17:54, 28 May 2016 (UTC)
 * Sorry, my usual approach is to pedantically pick holes in the bits that I don't like. I leave it as implicit that I approve of the stuff that I don't niggle about. I don't really disapprove of saying that something is "about the area of Florida", but I get the feeling that that's a can of worms. Archon 2488 (talk) 19:28, 28 May 2016 (UTC)
 * No worries. At another project page recently progress was obstructed by an admin with a distorted idea of what constitutes consensus and I didn't want a similar fate to befall this effort just for lack of explicit approval.  E  Eng  21:34, 28 May 2016 (UTC)


 * This is embarrassing, but I had been thinking the text we were discussing was a replacement for only the first paragraph (non-bulletted) of the current section i.e. to replace from "Where English-speaking countries use" to "some special reason to do so". I completely missed that the two bullets (especially the second of them) immediately after that first paragraph already addressed what we're discussing here, to some extent. In particular I didn't realize that Am. football was already being used as an example. I just wasn't looking. This also explains some of what and  comments which had puzzled me.


 * Anyway, since A8 hasn't got any significant comment, I've integrated those two bullets into it, which I hopes makes it more appealing for all parties. Sorry for the confusion. Are we getting anywhere?  E Eng  18:22, 28 May 2016 (UTC)


 * I have changed "mi2" to "sq mi" (as is more conventional) and got rid of microinches in favour of scientific notation I believe more closely matches what we would in practice use. There is no good conventional imperial unit at this magnitude because nobody uses imperial units at this magnitude, and I share reservations about microinches.  If this is controversial or undesirable, please feel free to revert.  Beyond this, I am broadly happy with this proposal. Kahastok talk 19:17, 28 May 2016 (UTC)

Discussion of A8
I think proposal of A8 is looking good, and applaud EEng's edit to concentrate further discussion in this area. I'll kick it off with a couple of comments:


 * Certain topics may benefit from a mixed approach...
 * The use of American football is an excellent example (I would disagree with a previous statement almost exclusively of interest to Americans since the topic is marketed in the UK, and probably in a number of other countries as well).
 * However, the guideline on mixed approach could include another example, where the primary unit is SI. I couldn't immediately think of a good example. The nearest I could come up with is one I mentioned earlier, main sequence, where the (non-SI) solar mass unit is reasonably explained in the intro, and thereafter only uses the symbol, which (like the mass of the earth) is pretty much impossible to express in kilograms/metric tonnes or any other unit that could sensibly provide any sense of scale. definitely can only be described as a MegaShitload unit.
 * I'll try and find an SI-based example, but feel free to chip in. (Pseudo sign Robevans123 (talk) 00:16, 29 May 2016 (UTC) - my later unsigned edit screwed my efforts to keep each bullet separate, so that subsequent comments can be easily added)
 * A possible alternative to the American football article might be Flight level where flight levels are described in feet only for the most part - it's certainly an article with worldwide interest although the number of visits is lower than for American football, but not so prone to seasonal variations. See |American_football comparison from Tool Labs for details. Interestingly, (from reading Metrication in the United States), many countries used metric values up until the end of WW II - rather unusual to have a standard switch from metric to USC units. BTW I also found that the US Navy still use kiloyards... Robevans123 (talk) 06:49, 29 May 2016 (UTC)


 * Certain topics will not benefit from any conversions or sense of scale
 * A new item to add to the guidelines. There are some articles where the units are so large or small that it is impossible to provide any sense of scale, and any conversion would be inappropriate, for example Ionizing radiation which uses the electronvolt (eV) extensively. No conversion to any unit of energy (joules, calories, etc) that we can relate to would be useful. The electronvolt is a MicroShitload.
 * Proposed wording of bullet:
 * Certain topics dealing with units of the very large or very small are beyond any sensible conversion and any conversion would be detrimental to the article, for example, Ionizing radiation. Just check the unit is spelt out in full and wikilinked on first usage.
 * -- — Preceding unsigned comment added by Robevans123 (talk • contribs)


 * This proposed wording is too vague. There are cases relating to ionising radiation (e.g. converting grays to rads or becquerels to curies) where you might want to offer a conversion. Moreover, there are cases at the "very small" end (e.g. instantaneous luminosity of a particle collider in nb-1s-1 or cm-2s-1) and at the very large end (e.g. AU to kilometres, megametres, gigametres, or ly to pc) where conversions might be desirable for various reasons.


 * There are obvious examples, I think, of where a conversion from SI would be useless. Converting the Earth's mass from kilograms to pounds, stones, hundredweights, etc. would be one such example, as I gave above. Archon 2488 (talk) 00:48, 29 May 2016 (UTC)


 * Yeah, I agree Re123's text ain't so good. I think this is another aspect of the most-cases-where-no-conversion-is-appropriate-are-science-topics thing, other facets of which are already given in A8's drug/visible light bullet, and sense-of-scale semiconductor/assay/giant star bullet. I think that within these three there's a simple principle struggling to get out -- we just haven't found it. I think it would help if "we" (not me -- I'll be traveling for a few days) could exhibit actual passages from e.g. ionizing radiation that should have neither conventional conversions nor a "sense of scale" thingamajig. From those maybe we can find a common theme.  E  Eng  02:24, 29 May 2016 (UTC)


 * Actually, I think we've already found it. Only convert into units that people in the English-speaking world might actually find useful in the context described.  IOW, we don't convert into "unknown or obsolete" units or units and only convert "where English-speaking countries use different units for the same quantity".  So far as I can tell this already covers scientific issues well enough.  If there's a scientific topic where conversions are useful to the reader, then we should convert.  But we shouldn't convert to units that are not likely to be useful to the reader.  We might add the words "this is likely to be common in scientific fields" to the "unknown or obsolete" point if we feel the need to specifically mention science, but I think the point is wider.  Similarly, there is surely also a sensible principle that we only provide a "sense of scale" comparison if it's useful to the reader and contextually appropriate.


 * There used to be a point in here that advised using units appropriate to the topic subject, contrasting something relatively general interest (something like Sun) where one might need to use common real-world units with something relatively technical and niche (I think it was Black hole evaporation) where it's fine to only use the technical units used in the fields.


 * Beyond that, don't convert repetitiously or in a way that actively disrupts the text. That covers "text dense with measurements", the American football example and the four-minute mile example. Kahastok talk 09:56, 29 May 2016 (UTC)


 * I mostly agree with Kahastok here. The MOS guideline needs to allow editors working on such a topic to use their discretion to decide which, if any, conversions are helpful. My main concern with what is proposed directly above is that we should not broadly declare ionising radiation as a topic where conversions and sense-of-scale equivalences are not relevant (disclosure: I know orders of magnitude more about ionising radiation than I do about American football, and I don't really have a horse in the race where the latter is concerned).


 * For example, if you're talking about an exceptionally energetic cosmic ray event, it might be helpful to point out that we're talking joules of energy (i.e. it is so energetic that it's of that order of magnitude), whereas in most cases there would be little point in converting eV to J. You'd just say that the unit used is eV, with a link to the article and perhaps the conversion to SI (1 eV ~ 160 zJ) on first use. Other comparisons (e.g. to the LHC collision energy, or to diagnostic or therapeutic X-ray energies) might be helpful depending on context, since these are the areas where eV are most commonly used.


 * Quantities that are nominal or defined might benefit from a conversion-or-equivalence on first use (i.e. no repetitious conversion), but on no account should we ever talk about the 247-acre array (this point is basically covered by the milligrams-to-ounces example, I think).


 * The concerns that were brought up above (SI units being deprecated or gigaseconds vs. years) are unlikely to ever constitute a problem in article space, so I continue to feel justified in "airily dismissing" them. Should I be wrong about that, we can always discuss later, but I would bet my life savings that it won't happen. MOSNUM should focus on practical concerns exclusively. Archon 2488 (talk) 11:44, 29 May 2016 (UTC)


 * I am happy to ignore deprecated or unknown SI units (and strangely you keep ignoring the "unknown" part of that), including gigaseconds, if you are happy with the principle that these rules should apply to all units symmetrically, with no required conversions to SI in those circumstances - wherever they arise - where those conversions are not useful to the reader.


 * Yes, I've brought units like gigaseconds and kilodays up before, because they serve a useful purpose. When people argue that SI should have some really special status, that we should always convert to it, that we should always use it in general articles - and that happens an awful lot - they are a useful reminder that SI is not always appropriate.  That we have to work with, not against, a real world that does not use SI alone and that we always have to consider context.  When you or anyone else advocates pure SI, or required conversion to SI, they are advocating kiloseconds, megaseconds, gigaseconds and so on whether they mean to or not.


 * I maintain that it is a statement of the obvious that if we were required to include a conversion to SI, then that requirement would necessarily include units of time. But I also note that I do not believe this is the effect of the proposal. Kahastok talk 12:20, 29 May 2016 (UTC)


 * Thanks ! But say what you mean - don't try to sugar coat the 100 mg pill! It was badly worded and overlapping somewhat. It was late at night, blood sugar level was low, seemed useful at the time, and unusually I made a slip (Freudian?) in omitting to sign the article...
 * It was certainly not meant as guideline that ionising radiation in general was off-limits for useful conversions, just that the article Ionizing radiation was a good example (and this is what I missed out in the bullet) of the shear pointlessness of trying to convert (either into other units or to give a sense of scale) electronVolt values in the 10-33 eV range. The article usefully uses conversions of other quantities later on (and even gets the banana equivalent dose in).
 * These energy comparisons give a useful range of typical values. I look forward to comparing the designed proton collision energy at the Large Hadron Collider as roughly equivalent to the kinetic energy of 14 flying mosquitos (fM). -;) Robevans123 (talk) 13:01, 29 May 2016 (UTC)


 * Re. deprecated and unknown: my position is that A) no SI unit has ever AFAIK been deprecated; if and when that happens we will certainly have something to discuss here, but I consider such an eventuality so far-fetched in the short term that there is no point considering it now; B) you've not provided a context in which SI is "unknown" (that's setting the bar extremely high – I can think of no case where SI has a unit that is as obscure as the furlong, let alone the pica, the gill, the grain, the scruple, the troy pound, etc.) so I'm not sure what you're getting at. SI has only one unit per physical dimension, and to the best of my knowledge none of them is obsolete or unknown. If you're saying that (for example) the conversion of megaparsecs to SI would be superfluous since SI is rarely used at such a scale, then fair enough, but "unknown" is too strong for the simple reason that if you did give the distance in zettametres or metres in scientific notation, people would recognise what it meant (I accept that whether it would be useful in said context is a different question); if you gave it in a unit that I would call effectively unknown, such as the pica, the vast majority of people probably would have no idea that it's a typographical unit which would never ordinarily be used in astrophysics. You don't need to call my position "strange"; you could just ask me to explain it more.


 * Expanding on this: my "(more or less) always convert to SI" position was shorthand for something more nuanced, which I considered too obvious to need to spell out. This is why I say I am a pragmatist rather than a literalist about what the MOS should be. Using hectares instead of hectometres squared is fine, as with litres and decimetres cubed, or tonnes and megagrams. In each of those cases, the formally equivalent SI term has a more commonly used synonym which is officially accepted by the BIPM, and providing the equivalent SI expression every time (e.g. glossing "15 mL" as "15 cm3") is obviously excessive. So far, so good. We do not need to convert litres per 100 kilometres to the more "orthodox SI" decimetres cubed per megametre.


 * The time units, as you have correctly if somewhat pedantically identified, are a thornier case. The BIPM accepts minutes, hours, and days as units that may be used with SI, but not weeks, months, or years. Above, I speculated as to why this might be (I don't actually know, and in any case it's well beyond the scope of this discussion). Since timekeeping standards have relatively little to do with the BIPM and SI beyond using the SI second as their base, however, this is an angels-on-pinheads matter; the number of days in a year comes down to astronomy, not a human-defined system of measurements. I consider it almost inconceivable that any editor in article space is going to be so confused by this that they will insist that the year is not an SI unit, or that they will actually object to an article referring to the duration between June 15 and August 15 as "two months". So, adding these minor caveats to my position would simply remove the non-problem. Archon 2488 (talk) 14:05, 29 May 2016 (UTC)


 * If you asked a man on the street in any country you choose to name how many metres were in a zettametre, how many do you think would know? I wouldn't be surprised if not one in ten thousand got it correct.  Even if you restricted it to asking Physics graduates, I'd still bet on its being a very small minority.  Less obscure than the furlong or the pica?  Maybe if you're in Russia or China, but in Britain and America I don't believe that for a moment.


 * If you wrote 100,000 lightyears (0.95 Zm), how many would know that "Zm" meant "zettametre", even linguistically? Again, I don't for a moment believe it's a large number.  By "unknown", that doesn't mean unknown to people who have studied the BIPM standards in detail.  It means unknown to the reader, most of whom have never studied Physics.  The zettametre is by any even vaguely sensible standard an unknown unit.


 * I maintain that all units should be treated in the same way, whether they are SI or not. I note that this is the current proposal, which does not imply any special treatment for SI.  This does not mean that conversions to SI will not in practice be more common - they almost certainly will be - only that in a given set of circumstances the decision as to whether to convert to a given unit should not depend on whether the unit in question is SI or not.  Perhaps it would help if you could give a circumstance in which your notion that SI should be treated somehow specially would be different from the situation where we treat all units symmetrically?  The above reads to me like you're saying that SI should be treated specially except in every circumstance in which that would mean treating it specially. Kahastok talk 20:59, 29 May 2016 (UTC)


 * That is an objection to a specific use of an SI prefix, not an SI unit per se. If the prefix "zetta" is not felt to be of utility, one is free to use metres in scientific notation instead (as I said in my original comment, and to which point you did not respond). In any case, SI prefixes are merely a shorthand for orders of magnitude, so it does not make sense to treat each prefixed unit as a separate unit in isolation.


 * The use of metres in scientific notation is not remotely uncommon in scientific contexts; indeed it is already what several relevant Wikipedia articles such as this one already do. I object to being patronised and dismissed for defending what is already done in practice, and I reject any suggestion that the use of metres in astrophysics is so unknown that it is in any sense comparable to furlongs or picas. Moreover, you have still not provided an example of when an SI unit is "unknown" (the tesla? Nope. The farad? Nope. The joule? Nope. Continue until you can answer "yes" and we're talking). Whether an editor chooses to provide a conversion to the prefixed SI unit or the un-prefixed unit in scientific notation is irrelevant to the point that I'm making.


 * Regarding the proposal, my concern here is that language about "deprecated", "unknown", or "obsolete" SI units should not appear, since I am not convinced that it is compatible with NPOV. As a simple, objective fact, SI units are not comparable to legacy units like the foot or "jargon" units like the megaparsec, because this is the consensus of every metrology organisation in the world, which should not be ignored. Ultimately, they are the authority on this, and Wikipedia is not. Wikipedia should respect the consensus of metrology organisations for the same reason that it respects the consensus of climatology organisations; to do otherwise is not NPOV.


 * The other point (exceptions to necessary SI conversion): I am not sure whether this even needs to be codified in MOSNUM, but the only exceptions I mentioned were where there are "synonyms" for SI that are officially accepted (the litre, hectare, etc.), and time units. OTOH, I cannot say that I am amused by the prospect of allowing a plethora of legacy units without conversion in certain topics simply because they have been sluggish in adopting SI (such as aviation) – this is what I was driving at. I am opposed to some misguided egalitarianism of units that disregards historical context, treating legacy units and modern units as equivalent when the science of measurement and reputable metrology organisations say that they are not. I realise that I am unlikely to persuade others of this, but I do not see that as NPOV. Archon 2488 (talk) 22:39, 29 May 2016 (UTC)


 * Ah, so you're going for no true Scotsman then?  You don't like the counterexamples given so you discount them and ask for more.


 * It is not neutral to systematically prefer one POV over units over another, much as you might prefer that it is. We work in the real world, not in an idealised world.  You refer to "legacy units" but these are units that are used by real people - yes, including real scientists in some fields - day to day in the modern world.  I find it difficult to see how it could possibly be considered neutral to push a given set of units in contexts in which they are not used for ideological reasons.


 * That said, I note with interest that you do not give any circumstance in which your your notion that SI should be treated somehow specially would be different from the situation where we treat all units symmetrically, as I akked previously. Kahastok talk 09:02, 30 May 2016 (UTC)


 * "It is not neutral to systematically prefer as more legitimate a PhD granted by Cambridge to one granted by Patriot Bible University". "It is not neutral to systematically prefer astronomy over astrology." There are cases where this false egalitarianism, treating cases as equal based on superficial characteristics, will let you down, and it will not lead to a NPOV. I do not accept that a POV on units of measurement formed by denying any special status to all the world authorities on measurement and neglecting the content of the science of measurement is neutral, nor do I need to accept that. What you are pushing is as least as much a POV as anything else that has been proposed here.


 * I gave a perfectly good rebuttal to your example, which means that I did not commit the fallacy you describe. My point is that you cannot name a physical dimension for which the appropriate SI unit is deprecated, obsolete, unknown, etc. Pointing out that most people do not know how to use large SI prefixes, while correct, does not address this point, and it does not mean that I have committed the No True Scotsman fallacy. In other words, there is no case I know of where no conversion you could provide to SI would be meaningful. To reiterate, my concern here was that none of this language should appear in the proposal; since at present it does not, we don't have too much to discuss here.


 * I gave the specific example of aviation, since that has been much discussed here. I reiterate my discomfort with allowing in any context the mass use of legacy units without conversion; I believe, at the very least, that the bar (if you will forgive the pun) here needs to be much higher than for justifying SI-only in a science article (or, to put the shoe on the other foot, for justifying that all the heights of trees in a botany article need to be converted to feet and inches). I don't think this is a crazy perspective, but I concede that it might be hard to codify at the level of the MOS. The present text "[c]ertain topic areas may benefit from a mixed approach" is a bit vague, and it leaves perhaps too much power in the hands of editors. But I I could be wrong about that, and until and unless that causes a problem in articles, I don't strongly object to it.


 * To come to some sort of conclusion: I do not strongly object to A8 as it stands, but I did have other peripheral concerns, which probably cannot be further addressed here. Archon 2488 (talk) 11:25, 30 May 2016 (UTC)


 * I don't think anyone's saying that conversions to metric shouldn't be common, even the default, applying most of the time, since in most fields they are standard. The only question is whether to give them some kind of special status when they aren't standard or routinely used.  As I say, you seem to be arguing that they should be, except for every time the situation arises.  I don't accept that.  They shouldn't be treated specially.  It's not neutral or beneficial to require any conversion - to metric or to non-metric - when they aren't useful to the reader.  But that is not to say - has never been to say - that conversions to metric units are not more likely to be useful to the reader in many fields than conversions to non-metric units.


 * In terms of "[c]ertain topic areas may benefit from a mixed approach", my argument would be that if you want to not convert - like any other exception - you need to be able to say why. Same as when we had people arguing that articles on Ukrainian cities should be miles first: why?  If you can correctly answer that based on the rules, fine.  If you can't, you have to convert. Kahastok talk 12:27, 30 May 2016 (UTC)


 * I'll be leaving for the airport in a few hours so this may be my last post here until Thursday. Let me strongly suggest that discussion goes best when posts offer concrete proposals (even if rough, tentative, or incomplete) for changes to the guideline text and examples.  E Eng  15:16, 29 May 2016 (UTC)

Propose adopting A8
I propose that Proposal A8 be incorporated into WP:MOSNUM. Kahastok talk 09:03, 30 May 2016 (UTC)


 * Support as this seems sensible advice as to when to provide conversions and when not to. Kahastok talk 09:03, 30 May 2016 (UTC)
 * Support I was gonna suggest waiting for more discussion and adjustment, but on reconsideration I think this is good enough to go in as is, though I'd be very surprised if more discussion and adjustment won't be needed on certain details. If there's significant dissent, however, we should suspend !voting and resume discussion on this page.  E Eng  06:05, 2 June 2016 (UTC)
 * Support A reasonable guidance on when to convert and not. Like all guidelines, apply commonsense and editorial discretion. Robevans123 (talk) 07:40, 2 June 2016 (UTC)
 * Support - much more well-thougt out than anything I could have proposed. FunkMonk (talk) 12:38, 2 June 2016 (UTC)
 * Much more well-typd out, too!  E Eng  13:17, 2 June 2016 (UTC)


 * Support – I don't see much reason to be concerned with the wording at present; if there are cases where it proves problematic in practice, then of course we can always discuss again. Archon 2488 (talk) 18:21, 2 June 2016 (UTC)
 * Support – has adequately addressed the concerns raised in the OP; caveats above could have gone without saying. Not that I would dream of accusing anyone here of verbosity. —Odysseus 1 4 7  9  00:06, 3 June 2016 (UTC)

Ping! I'm surprised not to have heard at this point from more of the usual suspects, such as. This would be a large addition, and it doesn't have to be perfect, but still I'd like to hear that others have no serious objections.  E Eng  18:05, 10 June 2016 (UTC)


 * Oppose because of (i) the proposal to end mandatory conversions (the introduction of the word "typically"); and (ii) the removal of the long-standing explicit allowance to avoid gobbledy conversions to British Empire units in scientific articles. Some of A8 is good, but my other issues are:
 * T1. What are "English-speaking countries"? India? There are more native anglophones in the Phillipines than in New Zealand. Do you mean "majority native English-speaking countries"?
 * T2. "Where English-speaking countries use different units for the same quantity"—Badly ambiguous.
 * T3. "will typically be used"—can't we use present indicative throughout? ("are typically used"). This applies also to "should be". Perhaps if absolutely necessary, but straight, simple, consistent grammar is better for the readers.
 * T4. "do not convert where it would make a common or linked expression awkward"—Why does linking an item make its conversion awkward? No example is provided, either.
 * T5. Why clutter up text with two non-metric conversions? This is over the top: "Where an imperial unit is not part of the US customary system, or vice-versa – and in particular, where those systems give a single term different definitions – a double conversion may be appropriate: Rosie weighed 80 kg (markup: ); The car had a fuel economy of 5 L/100km (markup:  )."
 * T6. What is wrong with "Florida"? Ash covered some 170,000 km2 (66,000 sq mi, or about the area of Florida) (Scale comparisons should have concrete meaning for most English-speaking readers, and should not be the closest match from an arbitrary list of candidates.)
 * T7. There's a MOS breach in "Earth-Sun distance".
 * T8. "In text dense with measurements, conversion of every measurement may add clutter to little benefit. In such cases judgment will dictate which, if any, measurements should carry conversions:"—the examples work nicely because the components make a range from low to high, with one conversation at either end. It would be nice if this logic was made clearer, or I can bet you editors will start inserting conversions at the start and end of non-ranged lists.

Tony  (talk)  04:05, 11 June 2016 (UTC)


 * Well, that's the last time I ping you! But let's see if I can talk you down off the ledge.
 * Re T1, T2, T4, T5. This stuff is all verbatim from the current guideline, so can we take up those issues later? (And there is indeed an example for your point 4.)
 * Re T3, T7. Can you just fix these? Please create a new Use version A9, below.
 * Re T6. Please be assured I have nothing against Florida itself. (Well, actually I do, but it's not relevant here.) My point is this: Florida has an area of 65758 sq. miles, Missouri 69707, Wisconsin 65496. Since the ash covered 66000 sq mi, we compare it to Florida, but if it were 65000 we'd be sayig Wisconsin, or if it was 70000 we'd say Missouri. No one but some geography-memorizing highschool geek (and an American one, at that) would be able to appreciate the difference; it's a kind of coded overprecision. Even for Americans, states other than Alaska, Texas, and maybe Californa (big!) and Rhode Island (small!) have very little meaning along these lines, and I can only imagine how helpful such comparisons are to a Brit -- about as helpful as "about the size of York" would be to me.
 * That leaves your points (i), (ii), and T8. Can you be more of your usual precise self in describing the problems you see, and what you'd like to be different? (And by "British Empire units", do you really mean US Customary?)
 *  E Eng  05:11, 11 June 2016 (UTC)


 * Oppose pending resolution of large number of suggested improvements. See above (my list, Tony1's, and prior comments). This is on the right track, but it's far too early for a forced !vote.  This is not a parliament/congress, and we should get it as good as possible the first time, not try to re-legislate it later.  — SMcCandlish ☺ ☏ ¢ ≽ʌⱷ҅ᴥⱷʌ≼  09:22, 11 June 2016 (UTC)
 * I've moved your list from an earlier section to just below here, to keep discussion more linear. I've also labeled both your and Tony's points (T1, T2, etc.) for ease of discussion. (I realize that upsets the indenting a bit.) I hope that's not objectionable.  E Eng  12:20, 11 June 2016 (UTC)


 * Still needs work. I agree with the general idea behind this – give more detailed advice that makes better sense in more contexts. But I have several particular objections, corrections, and suggestions:
 * S1. "United Consolidated Amalgamated Intergalactic GigaPharma Ltd." is ridiculously verbose, and violates MoS anyway (we don't add "Ltd", "Co.", "Inc.", etc. after company names). Either use a real example or a fake one, but make it concise.
 * S2. "not its 100 mg tablets and definitely not its 100 mg (0.00353 oz) tablets"  – remove "definitely"; it implies that the first "not" isn't "definite" and is really just a "maybe", and further implies that any "not"/"do not"/"do"/etc. in MoS (or any other guidelines) is really a "maybe" if not given with "definitely".
 * S3. "Popular gauges are 6.5 mm (​0.256 in), 9 mm, 12 mm, 16.5 mm, 20 mm, 25 mm, 30 mm, and 45 mm (1.77 in)." – This is pointless and wrongheaded, and we would never do this. It begs to have the missing values filled in, and if the conversion is useful for the first and last case, it will be useful for all these cases. In reality, such instruments would almost certainly not have both units on them. What is probably desired here is that people get an sense of the total range, in units familiar to them, and that the specific models be specified in the units actually used on them: Popular gauges are in the 6.5–45 mm (0.256–1.77 in) range, most commonly: 6.5 mm, 9 mm, 12 mm, 16.5 mm, 20 mm, 25 mm, 30 mm, and 45 mm.  Furthermore, if the instrument in question really did use both units conventionally, it would not be likely to use "0.256 mm", but the closest fraction, and probably divisible by 2 (often by 4 or even 8), and in standardized patterns. So, in such a case we would use the actual fractional inches shown on the gauge, and provide it for each named gauge. If the gauges conventionally only provide one unit not both, we would just specify the one, and provide conversion for the range.  We needn't say all that here, just get the example to make sense in the context of actual articles written about actual gauges.
 * S4. "In some circumstances secondary" needs a comma between "circumstances" and "secondary".
 * S5. "if not allowable under WP:CALC" – Give the full location, WP:No original research, don't use shortcuts in actual guideline wording, since they are meaningless to people who do not already possess "WP:EXPERTISE" (well, we can get away with "WP:" for "Wikipedia:" in the running prose, but in hatnotes we even spell that part out).
 * S6. All of this example code needs to use non-breaking spaces between the values and the units.
 * S7. Piped links like "radius of the sun" should be given as not  . While it is not, the completely  capitalization of the real article name at the start of the piped link is part of how we insta-recognize one of these as a piped link in a small fraction of a second when looking at code, without having to parse it visually in detail.
 * S8. We should add a recommendation (unless it's already present in other text in this section) to not provide conversions to unusual or obsolete units. Weight weight should not be given a conversion to Stone (unit) for much of anything; Britons understand this unit when it is applicable (e.g. to British athletes), but they also understand the kg version, so there's no need for the stone version, and it should not be given for the weight of a motorcycle or a donkey. Similarly, Hand (unit) should never be provided for anything but livestock conventionally measured with this unit.
 * S9. "Visible light is usually defined as having wavelengths in the 400–700 nm range" should be Visible light is usually defined as having wavelengths in the 400–700 nanometer range. Other examples also need to illustrate that an unit that is not an everyday one for average people (ft, kg, etc.) should be spelled out in full and linked on first occurrence. Remember that people come to these sections
 * S10. "star of radius 257 million kilometres" is awkward nerdspeak; use plain English: "star with a radius of 257 million kilometres".
 * S11. Agree with above comment that the section on mixed usage should also provide an SI example, so people don't think this is some kind of "be gentle with the stupid Americans" thing. I would suggest pool (pocket billiards) as a good example, it actually uses mixed systems of units. Tables are given in foot approximations regardless of location (e.g. "a 9 by 4.5 foot playing surface"), though often given in cm or mm in official pro competition specifications, cue weights are given in ounces or grams depending on location, ball sizes are given in inches or mm depending on location, and cue tip widths are always given in mm, even in the US.  A complex example, e.g. for three-cushion billiards, can be cribbed from that article and/or from details at billiard table, billiard ball, and cue stick.
 * S12. Also agree with above comment: "There are some articles where the units are so large or small that it is impossible to provide any sense of scale, and any conversion would be inappropriate".
 * I have no pored over all the comments, and might well concur with others; I mostly just read version 8 and observed where I saw it was lacking. (And don't be discouraged; a rewrite of this level of detail and complexity takes work, and many editors from different editing spheres will notices different kinds of gaps, loopholes, etc.)
 * — SMcCandlish ☺ ☏ ¢ ≽ʌⱷ҅ᴥⱷʌ≼  09:20, 11 June 2016 (UTC)


 * My comments on SM's points:
 * Re S1. I know you're a Scotsman but still you may vaguely recall what a joke is. MOS need not adhere to MOS, and if anyone points to this example to bolster his side in some style argument, we can simply issue an instant WP:CIR block.
 * Re S2. See MOS:DECADE.
 * Re S6. I figured I'd add the nbsps and stuff when (if) this actually goes into the guideline.
 *  E Eng  12:51, 11 June 2016 (UTC)
 * In order:
 * S1: MoS absolutely does have to follow its own rules, or no one else will, obviously. Humor is fine, but not when it's ridiculously longwinded and makes it difficult to get to the actual advice. This is a guideline, not a humor essay.
 * S2: Your response does not address my point, which has nothing to do with decades at all.
 * S6: Better to do it now, so there is no doubt.
 * I have not yet looked over A9 to see whether it addresses the rest of my and Tony1's points (nor those of others).  — SMcCandlish ☺ ☏ ¢ ≽ʌⱷ҅ᴥⱷʌ≼  20:27, 15 July 2016 (UTC)
 * In order:
 * S1: MOS applies only to articles, not to talk pages and not to project pages. MOS itself doesn't consistently use either American or British English, nor does it follow its own formatting and layout rules, nor does it avoid speaking colloquially and instructing the reader, and to insist that it do these things would be hobgoblin consistency since articles, and MOS itself, serve quite different purposes. But anyway, the overlong example was intended just for the amusement of discussants here -- I never expected it to survive (but if it did, so what?). Like everything else you would like to see changed, why don't you just change it instead of all this endless chewing things over?
 * S2: Yes, your point has nothing to do with decades, but it does have to do with the text at DECADE -- read it.
 * S6. No, once we're all agreed on the substantives, I'll add internal formatting as a last step. To so earlier just makes discussions more confusing.
 * A9 does not address yours and Tony's points -- it's the same for now as A8, because it's intended to be a place for you two to make such changes as you will, so that others can discuss (though I think there will be little or no problem). Will you please do that now, after which we can re-ping Tony?  E Eng  19:36, 17 July 2016 (UTC)
 * Haven't touched it, honestly. Got involved in other projects. I'll try to move this toward one of the front burners.  — SMcCandlish ☺ ☏ ¢ ≽ʌⱷ҅ᴥⱷʌ≼  01:04, 21 August 2016 (UTC)

Proposal A9
I have an important deadline in two weeks so I really shouldn't be spending time on this, no matter how much I enjoy the company of my esteemed fellow editors. I'm even going to unwatch for that time -- let's see how long I can stay away. I wonder if and  can integrate their thoughts and comments into Version A9 (here), to the extent they think such changes won't be controversial. (This has been a pretty chill discussion, so be bold.) Remaining, less easy, points can then be hashed out further down. Good luck, my friends.  E Eng  12:51, 11 June 2016 (UTC)


 * Where English-speaking countries use different units for the same quantity, the "primary" quantity will typically be followed by a conversion in parentheses. Generally, conversions to and from metric units and US or imperial units should be provided:
 * &bull;  the Mississippi River is 2320 mi long (American topic)
 * &bull;  the Murray River is 2508 km long (Australian topic)
 * However, do not convert where it would make a common or linked expression awkward (The four-minute mile).
 * ''In some circumstances secondary units are unknown or obsolete in the topic area, and of little or no value to the reader:
 * &bull;  United Consolidated Amalgamated Intergalactic GigaPharma Ltd. withdrew its 100 mg tablets not  its 100 mg tablets and definitely not its 100 mg (0.00353 oz) tablets
 * &bull;  Visible light is usually defined as having wavelengths in the 400–700 nm range not the 400–700 nm (15.8–27.6 × 10-6 in) range
 * In text dense with measurements, conversion of every measurement may add clutter to little benefit. In such cases judgment will dictate which, if any, measurements should carry conversions:
 * &bull;  Popular gauges are 6.5 mm (​0.256 in), 30 mm (1.18 in), and 45 mm (1.77 in).
 * Popular gauges are 6.5 mm (​0.256 in), 9 mm, 12 mm, 16.5 mm, 20 mm, 25 mm, 30 mm, and 45 mm (1.77 in).
 * Certain topics may benefit from a mixed approach e.g. American football:
 * &bull;  The field is rectangular, 120 yards (110 m) long and $53 1/3$ yards (48.8 m) wide, with goal lines marked 10 yards (9.1 m) inward from each end...
 * Note: This section discusses movements of the ball in units of yards (0.91 m), as is standard in the sport. On a kickoff, the ball is placed at the 35-yard line of the kicking team (the 40-yard line in high school play). If the offense advances ten or more yards in the four plays, they are awarded a new set of four plays. If they fail to advance ten yards, the ball is turned over to the defense...
 * Where an imperial unit is not part of the US customary system, or vice-versa – and in particular, where those systems give a single term different definitions – a double conversion may be appropriate: Rosie weighed 80 kg (markup: ); The car had a fuel economy of 5 L/100km (markup:  ).
 * In some cases, it may be helpful to provide a sense of scale instead of, or in addition to, a conventional conversion (though a source may be needed for such comparisons, if not allowable under WP:CALC):
 * &bull;  fabrication of semiconductor devices as small as 14 nm (about 63 silicon-atom diameters)
 * &bull;  precise assays are possible on samples as small as 0.1 ml (about the size of a pinhead)
 * &bull;  a giant star of radius 257 million kilometres (160 million miles, about 370 times the radius of the sun and 1.72 times the mean Earth-Sun distance)
 * &bull;  Ash covered some 170,000 km2 (66,000 sq mi, or about the area of Florida) (Scale comparisons should have concrete meaning for most English-speaking readers, and should not be the closest match from an arbitrary list of candidates.)
 * Converted quantity values should use a level of precision similar [etc etc]
 * Converted quantity values should use a level of precision similar [etc etc]


 * So, I'm gone two weeks and what happens in the meantime is... nothing? and, most of your concerns can fixed by simply editing A9 -- can you do that so we can then focus on what's left over?  E  Eng  19:40, 26 June 2016 (UTC)
 * Just one big waste of time, then?  E Eng  13:51, 4 July 2016 (UTC)
 * Yes?  E Eng  04:30, 15 July 2016 (UTC)
 * Honestly, I'm having a hard time getting enthused about this. The present wording has been working okay, in conjunction with WP:COMMONSENSE. If it needs some adjustments, they should be very minor, designed to encourage conversion everywhere it's genuinely useful, and to discourage it where it's just noise, without dumping a truck full of examples, per WP:CREEP.  I sympathize with the goals, but suspect that what's drafted above will open more loopholes than it closes, and further enable the already too-prevalent practice of US stuff not providing metric equivalents or vice-versa when these would actually be useful in the context. That is a far greater problem than the occasional one of someone providing conversions that are actually pointless. That said, if the A9 revision solves all of the objections Tony1 and I raised about A8, I wouldn't see any problem considering A9 as a refined A8 and counting the supports for A8 as supporting A9 also, if this ends up with a formal closer, and the closer wants to go that way (which would actually be pretty standard-operating-procedure to do in such a case, but I don't think a formal close is needed).  — SMcCandlish ☺ ☏ ¢ ≽ʌⱷ҅ᴥⱷʌ≼  19:49, 15 July 2016 (UTC)
 * Definitely not a waste of time, but I'm not sure of the way forward to bring it to a conclusion. After some long discussions and various proposals, I do think it would be better if the fresh eyes of and  could edit A9 to their satisfaction.
 * I'm not convinced that the current wording in conjunction with WP:COMMONSENSE is working - this whole discussion started on a conflict between commonsense and the current wording on some scientific articles...
 * Also, I'm not sure if having formal statements followed by examples is necessarily WP:CREEP. Some people learn and understand better through abstract statements and some people learn and understand better from examples. Robevans123 (talk) 16:17, 20 July 2016 (UTC)
 * It's on my to-do list, but I'm super-busy this week (off-WP). I'm not disinterested in this, I just don't have the cycles for it right now.  I guess there is no rush.  Aside from the item-by-item concerns above, as I recall from previous discussions along similar lines, Tony1 has raised dual concerns which are not necessarily easy to reconcile (and I tend to concur):
 * There's a tendency to skip conversions (that would be useful) when, e.g., an American editor or group of editors is writing about an US-centric topic, and seems to an American audience in mind, losing sight of the fact that this is a global work (and I can confirm, as an American, that the opposite can also happen, with .uk, .au, European, .hk, etc., topics often lacking conversions of metric distances and such into US customary units).
 * There's also, however, a tendency to inject pointless conversions to US and imperial units into scientific contexts where this is not actually helpful. In my own words, I would offer the rule of thumb that if you can change the number by an entire order of magnitude and the conceptualization in the average reader's head would be about the same, then the conversion serves no purpose at all – no one needs to know, or can really  how far it is to Alpha Centauri in miles (or in KM), nor can we really picture how small the RNA molecule is in a ridiculously fractional inch measurement.
 * I would add the third point that there's also a strong tendency of units peculiar to a topic not being converted when useful (what exactly is a hand of height in horses? And be aware that North Americans and many other non-British have no concept of how many stone the average man or woman weighs), yet a contrariwise tendency to convert like mad when doing so is not very helpful (e.g. in "deep" science topics that often, per #2 above, are discussing things so vast or small that conversion is uninformative). This is basically both a specialized-style fallacy and the Dunning–Kruger effect at once (and both forms of the latter at once): The person to whom the unit is intimately familiar and an everyday term thinks "one knows how big a furlong and a cable are, surely!"  Meanwhile "Randy in Boise" thinks "body knows what the hell a light-year is".  Both assumptions are false.  Also, we have wikilinking, and articles on units, for a reason.  That's all I've got time for right now. It's 1:30am my time, and I have to be up early.  — SMcCandlish ☺ ☏ ¢ ≽ʌⱷ҅ᴥⱷʌ≼  08:34, 21 July 2016 (UTC)


 * -- have you done all you can to A9 to address your own concerns? And if so, what's left to hammer out?  E Eng  00:54, 21 August 2016 (UTC)

Proposal B1
I disagree that we need to change the guidance, the sub point already clarifies what is meant by this. But if we must 'clarify' the guidance, let's go with this
 * Where English-speaking countries use different units for the same quantity, follow the "primary" quantity with a conversion in parentheses: the Mississippi River is 2320 mi long; the Murray River is 2508 km long. In science-related articles, however, supplying such conversion is not required unless there is some special reason to do so is not usually required, but can sometimes be helpful. If unsure, discuss on the article's talk page.
 * When units are part of the subject of a topic – nautical miles in articles about the history of nautical law (5 nautical miles), SI units in scientific articles (a 600-kilometer asteroid), yards in articles about American football – it can be excessive to provide conversions every time a unit occurs. It might be best to note that this topic will use the units (possibly giving the conversion factor to another familiar unit in a parenthetical note or a footnote), and link the first occurrence of each unit but not give a conversion every time it occurs.
 * In science-related articles, instead of conversions to imperial units, it may be helpful to provide a sense of scale instead. For example, Aldebaran is an orange giant star with a radius of 61 million kilometres (44 times the radius of the sun) or a 14-nm design (about the size of 63 silicon atoms).

Headbomb {talk / contribs / physics / books} 13:36, 22 May 2016 (UTC)
 * The point isn't just that we need to clarify further, but mainly that exclusion of conversions should be the exception, not the rule. FunkMonk (talk) 13:41, 22 May 2016 (UTC)
 * Systematic conversions like "a dissipation power of 100 W (341.2 BTU/h)" or "a 20 mg (0.00071 oz) dose of fluoxetine" are nothing but clutter and utterly pointless. Conversions should be a matter of editorial judgment, and usually left out unless there's a reason to include them. The height of a plant? Probably should have a conversion because that's an every day thing. The power output of a supernovae? The surface gravity of Ceres? The mass of an electron? Conversions not needed. Headbomb {talk / contribs / physics / books} 14:14, 22 May 2016 (UTC)
 * Which is exactly why it should be the exception ("not needed in highly technical sections"), not the rule. A huge bulk of our "science-related articles" are about "everyday things", including animals, plants, technology, and tonnes of other subjects. Wikipedia is not written for experts. FunkMonk (talk) 14:18, 22 May 2016 (UTC)
 * The opening sentence of Proposal B1 reads "Where English-speaking countries use different units for the same quantity..." - please can we see some examples of where America (for example) uses BTU/h for power output? Or 10,000ths of a ounce for medical dosage? Or slugs for the mass of meteors? Or supernovae output in anything but Foes (a non-SI unit...)? Or electron mass - anything apart from kg (to a very small magnitude), MeV/c2, or atomic mass units?
 * However, I do like the note on providing a sense of scale (but if kilometres are good, then why not miles as well?).
 * And if we're going to talk about Ceres:
 * "Its diameter is approximately 945 km" - from the article
 * "This image was taken by the Dawn spacecraft on 2 May 2015, during a "rotation characterization" orbit, 13,642 km above the surface of Ceres." - from the article
 * Unfortunately, mass, surface temperature, and gravity are only given in the infobox (without conversion - but the gravity is given in m/s2 and standard gravities). Looking at Vesta 4, I note that most crater dimensions are given kilometres and miles and surface temperatures are given in degrees centigrade Celsius, not Kelvin. So it seems that asteroids and dwarf planets use a number of conversions to about the right level (although they could possibly be improved by a bit more conversion), but they are certainly not cluttered by the conversions that are present.
 * And in checking on drug doses I came across the General considerations section in the Pharmacology WikiProject's Style Guide, which explained why drug dosages are not commonly given in Wikipedia articles, and also stated "Finally it is important to keep in mind that we are writing a general encyclopedia, intended to be read by the lay public so it is important to make technical material as accessible as possible to a wide audience but at the same time, not reducing the value of the article to more technical readers including medical doctors, pharmacists, and scientists."


 * Which I think neatly summarises what we should be trying to achieve in any recommendations on the use, or not, of conversions in the style guide... Robevans123 (talk) 20:45, 22 May 2016 (UTC)


 * To answer your questions: BTU/h would be a standard unit in some US industries, for example in measuring the energy consumption of radiators. It would not be common in a scientific context, which is what we are discussing here. Nor would the use of decimal avoirdupois ounces. The choice of units used in science is (in most fields) quite minimalist; when nonstandard units are used on WP, they should always be converted to SI, since even a scientifically literate person cannot be expected to understand the minutiae of obscure units that do not exist outside of certain fields (astrophysics is perhaps the worst offender in this regard).


 * I am opposed to opening the door too much to "conversion proliferation" because I don't see where it ends; converting asteroid masses to pounds or stones, or their dimensions to statute or nautical miles, or to something else (furlongs? cables?), is just not very purposeful. Fact is that all those units would be more or less equally unlikely to appear in a reputable scientific source. There are lots of nonstandard units which might be used to give such dimensions, but that does not mean that WP ought to provide those dimensions in such units.


 * I don't think that "highly technical" can be the guideline either. For one thing, that is vague. For another, there are many non-highly-technical scientific subject areas where the use of non-SI units would be quite unusual, and even some highly technical areas where non-SI units are common.


 * So to reiterate: I think that the default guideline in any science-related article should be to default to SI+friends, with optional conversions to any other units which might be used by reputable scientific sources in the relevant field (I am cautious about talking of "the rule" and "the exception" since I do not know how often such an "option" would be exercised). In practice, this is not vastly different from what happens in many science articles at present. Archon 2488 (talk) 15:20, 27 May 2016 (UTC)


 * I commented under Tony1's remark in section below.  Basically, I think that this idea that readers need a lot of help understanding SI units, though there may be some truth to it, is leading us into making a real mess of articles, and not providing much real value for it.  Does a reader relate better to an astronomical number of miles than kilometers?  No; readers know these units are "comparable" and that's all they need to know.  Or miniscule parts of liters or meters, compared to other units?  No; they aren't going to get any more out things like 0.0002 inch than the equivalent SI units.  The wingspan of a bird?  Sure, why not?  But we get carried away when we start describing football fields and their goals 9.1 meters in from the ends.  Some advice toward using conversions only when they seem to actually be helpful would be a nice direction while we're at these revisions.  Generally, I'm more aligned with Headbomb and Archon 2488 than with FunkMonk and EEng on this, but I think that  Archon 2488's advice applies more broadly than to science-related articles.  Dicklyon (talk) 16:53, 11 June 2016 (UTC)
 * Yep. We deal with this in cue sports a lot, where some things are given in mm even in the US and some in imperial units even in the UK, just as matters of evolved tradition. It is helpful to convert in these cases when describing the entire range of sizes, and thereafter to use only the customary units for the thing in question.   — SMcCandlish ☺ ☏ ¢ ≽ʌⱷ҅ᴥⱷʌ≼  19:46, 15 July 2016 (UTC)

Phantom clutter
What I find problematic with the above is the following. ''In text dense with measurements, conversion of every measurement may add clutter to little benefit. In such cases judgment will dictate which, if any, measurements should carry conversions:''
 * &bull;  Popular gauges are 6.5 mm (​0.256 in), 30 mm (1.18 in), and 45 mm (1.77 in).
 * Popular gauges are 6.5 mm (​0.256 in), 9 mm, 12 mm, 16.5 mm, 20 mm, 25 mm, 30 mm, and 45 mm (1.77 in).

It appears as if this was deliberately contrived to look awful. They say "Never attribute to malice that which is adequately explained by stupidity." though. (I don't mean to insult anyone, this is just the way the phrase goes.) Seriously, though, who would write this way? It's horrible and should not be encouraged by inclusion in the MOS. A writer with an ounce (28.4 g ... {jokes}) of style would write
 * "Popular gauges are 6.5, 30 and 45 mm (0.256, 1.18 and 1.77 in)."

not this hideous
 * "Popular gauges are 6.5 mm (​0.256 in), 30 mm (1.18 in), and 45 mm (1.77 in).".

Likewise,
 * "Popular gauges are 6.5 mm (​0.256 in), 9 mm, 12 mm, 16.5 mm, 20 mm, 25 mm, 30 mm, and 45 mm (1.77 in)."

should become
 * "Popular gauges are 6.5, 9, 12, 16.5, 20, 25, 30 and 45 mm (​0.256–1.77 in).".

However, now that this is rewritten more sanely, we can see that we're not going to get anything as ridiculous as
 * "Popular gauges are 6.5 mm, 9 mm, 12 mm, 16.5 mm, 20 mm, 25 mm, 30 mm and 45 mm"

anyway. Instead, this would become
 * "Popular gauges are 6.5, 9, 12, 16.5, 20, 25, 30 and 45 mm (6.5 mm, 9 mm, 12 mm, 16.5 mm, 20 mm, 25 mm, 30 mm and 45 mm)",

which, of course, is still very ugly but not nearly as bad. On the other hand, though, what's the use of such a sentence anyway? If we've got a list as long as this, the best way to deal with it would be to put the values in a table and then you'll not have to worry about the clutter at all. No, we don't want to add clutter but what's going on here is merely doubling the clutter already there. If we don't fancy clutter, don't have it in the first place. I get the general thrust of what is being discussed here but I think the example is terrible. Is there even a good example we could use or might it be that, in all such cases, it's merely an artifact of bad style that we end up with long lists of values in prose? Should there ever be text dense with measurements? Jimp 04:28, 4 June 2016 (UTC)


 * Completely agreed with Jimp on this. The "" mess is ridiculous, and we would fix this on sight to "Popular gauges are 6.5, 9, 12, 16.5, 20, 25, 30 and 45 mm (​0.256–1.77 in)."  That "Popular gauges are 6.5 mm, 9 mm, 12 mm, 16.5 mm, 20 mm, 25 mm, 30 mm and 45 mm" example is ridiculously contrived and bogus, being used to suggest a massive problem that does not actually exist.  — SMcCandlish ☺ ☏ ¢ ≽ʌⱷ҅ᴥⱷʌ≼  16:29, 15 July 2016 (UTC)

Pointer to proposal to change ref spacing after a number
Please see Wikipedia talk:Manual of Style (the proposed change would probably end up in MOSNUM not in the main MOS page). — SMcCandlish ☺ ☏ ¢ ≽ʌⱷ҅ᴥⱷʌ≼  00:36, 22 August 2016 (UTC)

Date retain argument at Evo 2015
I'm dealing with a dispute over at Evo 2015 related to Date Retain, where I user named is insistant that all the dates within the article's sources should be changed to match those within the article prose. (first change) This argument seems rather convoluted to me? After all, the "yyyy-mm-dd" format can't even be used in prose last time I checked. Surely, this is not how the guideline was intended? There are some other issues as well, such as that the prose dating-style has changed a bit since I brought the article in the mainspace, and that to undo Tony1's change in date-format, I keep undoing his other changes during that edit as well >.> ~ Mable ( chat ) 19:09, 24 August 2016 (UTC)
 * WP:DATEFORMAT would seem to indicate that the use of YYYY-MM-DD is indeed permissible in citations. --Izno (talk) 21:04, 24 August 2016 (UTC)
 * No. Unfortunately these rules are the wreckage of a decade-plus of arguing, they're pretty complicated, and really have to read the entirety to be sure your getting all the exceptions and notes. See WP:DATEUNIFY -- yyyy-mm-dd is OK for access and archive dates only, not publication dates.  E Eng  21:50, 24 August 2016 (UTC)
 * The third point of "publication date" at DATEUNIFY explicitly says that yyyy-mm-dd is allowed for regular publication dates, Eeng. I've read through these guidelines a year ago and concluded that that format suits my preference the best. I've also seen it used on a lot of pages, so I kinda took it as a "Wikipedia standard". ~ Mable ( chat ) 22:34, 24 August 2016 (UTC)
 * "Publication dates ... may be ... the format expected in the citation style." And at WP:CITESTYLE we have, "Although nearly any consistent style may be used, avoid all-numeric date formats other than YYYY-MM-DD." Which seems to say that YYYY-MM-DD is acceptable. And we usually don't do mass style changes without a good reason or at least a talk page discussion. I'm not crazy about this style but MOS seems to say it's ok. Kendall-K1 (talk) 23:01, 24 August 2016 (UTC)
 * Oops, sorry, I read hastily and got distracted by something else. My apologies.  E Eng  05:00, 25 August 2016 (UTC)
 * Haha, it's alright - don't commit Seppuku just yet. I'm just glad I'm the one not going crazy :) ~ Mable ( chat ) 07:30, 25 August 2016 (UTC)

Double prime for inches
Prompted by a comment in another discussion above, and maybe this is a question for WikiProject Military history. We've got these two similar articles, one with quote mark and one with double prime:
 * 3"/23 caliber gun
 * 3″/50 caliber gun

Are both acceptable? Then there is also for example 3-inch M1902 field gun. Kendall-K1 (talk) 13:00, 30 August 2016 (UTC)
 * No. See the specific-units table right at the top.  E Eng  16:32, 30 August 2016 (UTC)


 * That actually says both are equally unacceptable. The problem with that is that 3"/23 is a pretty standard name for this gun, as used in the reliable sources. So if you consider it a name rather than a measurement, I think it's acceptable, but still don't know which glyph to use. I agree that it would be incorrect to say, for example, "this gun has a barrel that is 3" in diameter." Kendall-K1 (talk) 18:05, 30 August 2016 (UTC)
 * Sorry, I didn't look closely enough at the usage the OP was discussing (excuse: I was on my mobile) and was responding only to the 3" bit. Kendall's response is exactly right.  E Eng  18:41, 30 August 2016 (UTC)

Centuries and millennia
I've come across something in Manual of Style/Dates and numbers that puzzles me. It is in the section on Centuries and millennia at MOS:CENTURY. The first indented bulleted item within the first main bulleted item is:


 * The 18th century (1701–1800) and the 1700s (1700–1799) are not the same period.

This is perfectly clear to me, and I'm glad it is here because this is often misunderstood.

The second indented bulleted item just below that is:


 * When using forms such as the 1700s ensure there is no ambiguity as to whether e.g. 1700–1709 or 1700–1799, is meant.

This, I find confusing. What is the point of singling out 1700–1709 and contrasting it with 1700–1799? To me, any confusion between those would most likely be a matter of typing or keyboarding in the right numbers. It would make more sense to me if the first range were 1701–1800. Then the contrast would be between the years of the 18th century and the years of the 1700s, and this sentence would be further support for the first bulleted item.

I was also going to say that I think "the 1700s" (in "When using forms such as the 1700s") should be in bold or highlighted in some way when I realized that it is in a different font and, if my eyes are seeing correctly, slightly green in color. I can't believe this shade of green is being used for highlighting words, phrases and numbers on this page. Is it just my eyes? To me, it is such a dull shade of green, and not much darker than the text surrounding it, that it doesn't stand out. I think the color used for words, phrases and numbers to be highlighted (kind of like putting them in quotation marks) should be either a brighter shade of green or bolded or otherwise highlighted. – Corinne (talk) 01:13, 31 August 2016 (UTC)


 * This second point is separate from the first. The ambiguity is between the 1700s as a century (1700–1799) and the 1700s as a decade (1700–1709). Maybe this could be made more clear? Kendall-K1 (talk) 02:21, 31 August 2016 (UTC)
 * I clarified .  E Eng  02:30, 31 August 2016 (UTC)


 * As for the font color contrast, I can't find much about contrast ratios between fonts, but there is much written on the subject of contrast between font and background. ISO and ANSI recommend a minimum of 3:1, and W3C recommends 4.5:1. The ratio between our green (which is W3C "dark green") and black is 2.82:1. The contrast between dark green and black is very apparent to me, but it will depend a lot on your screen technology and settings. Kendall-K1 (talk) 02:35, 31 August 2016 (UTC)


 * Oh, now I get it. Thanks, Kendall-K1 and EEng. However, how often do people really say "in the 1700s" to mean "some time during the years 1700–1709", or "the whole period from 1700 to 1709"? I don't think it's very often. I think what is more common, and clearer, is "in the first decade of the 1700s", "during the first decade of the 1700s", or "during the first decade of the 18th century". Perhaps we could suggest some of these wordings. – Corinne (talk) 23:01, 31 August 2016 (UTC)
 * P.S. Regarding the green color of the highlighted text, I barely see the green color at all, but I clearly see the green color of the bullets next to changes to articles on my watch list. – Corinne (talk) 23:03, 31 August 2016 (UTC)
 * Odd, it's the exact opposite for me. I can barely make out those green dots. In theory, the fonts at least should be customizable by setting your own user css, but I have never been able to get that to work. If you want to try, it's under Preferences -> Appearance -> Skin. Click on "Custom CSS" which will probably be a redlink. Create the page and put your css in it. Kendall-K1 (talk) 23:19, 31 August 2016 (UTC)
 * Thank you, Kendall-K1! Maybe I will, even though that kind of thing is a bit of a mystery to me. – Corinne (talk) 23:33, 31 August 2016 (UTC)


 * I'm not sure of the precise wording, but perhaps we should consider depreciating the use of the term "the 1700s" etc.
 * "The 1700s" is ambiguous. It could mean 1700-1799 or 1700-1709.
 * If "the 1700s" refers to the decade 1700 to 1709, it would be better to specify the years rather than using an ambiguous term.
 * If "the 1700s" specifically refers to the century 1700-1799, it would be better to specify the years rather than using the ambiguous term.
 * In many cases *The 18th century" (1701-1800) is an unambiguous substitute even though 1701-1800 is not the same as 1700-1799.
 * Michael Glass (talk) 00:37, 1 September 2016 (UTC)


 * I've boldly made a change from 1700s to 1900s, since (as Corinne said) it's rare for anyone to intend the 1700–1709 decade when saying "the 1700s", but it's quite common for this to be the case when either "the 1900s" or "the 2000s" is said. This change also removes any confusion about this point being related to the one immediately preceding it. —  Crumpled Fire   • contribs • 00:54, 1 September 2016 (UTC)

BC/BCE
I support getting rid of BC/BCE in the examples. You would never see this in a WP article. The example should match what you would see in article text, unless it's an example of what not to do. Which this isn't. Kendall-K1 (talk) 02:28, 1 September 2016 (UTC)


 * Which examples? Are you talking about the entire MOS:ERA section or this sentence: Treat the 1st century AD as years 1–100, the 17th century as 1601–1700, and the second millennium as 1001–2000; similarly, the 1st century BC/BCE was 100–1 BC/BCE, the 17th century was 1700–1601 BC/BCE, and the second millennium 2000–1001 BC/BCE. ? If the former, we definitely need that section. If the latter, the point is not to say to use "BC/BCE" but that either one is acceptable/applicable.  McLerristarr &#124;  Mclay1  03:27, 1 September 2016 (UTC)
 * BC and BCE are alternatives, and where the guideline text says BC/BCE it means "either BC or BCE, whichever". Only one or the other would actually be used. You'll notice that BC/BCE doesn't appear in actual examples -- our editors are smart enough to understand that this.  E  Eng  03:31, 1 September 2016 (UTC)
 * I am agreeing with Crumpled Fire's comment and edit, "BC/BCE shouldn't be used together here." Yes, I know these are not examples in the red/green font sense of the word. Kendall-K1 (talk) 03:59, 1 September 2016 (UTC)
 * The intent seems clear enough to me, but I suppose it wouldn‘t hurt to say something like 100–1 BC (or BCE) and so on. Until someone decides to interpret it as expressing a preference for the era not parenthesized, that is. —Odysseus 1 4 7  9  05:22, 1 September 2016 (UTC)
 * I thought of this, but it gets tiresome repeating that over and over. BC/BCE means the same thing, and as I said, our editors are smart enough to understand. No one's gonna actually think they're supposed to write "He died in 5 BC/BCE."  E Eng  05:51, 1 September 2016 (UTC)
 * It needn’t be used every time; at the first occurrence in a series ought to be enough.—Odysseus 1 4 7  9  07:36, 1 September 2016 (UTC)


 * Is it clear whether this thread concerns communication with editors or readers? Tony   (talk)  08:34, 1 September 2016 (UTC)
 * I was responding to a revert on the project page, so editors only. Kendall-K1 (talk) 15:02, 1 September 2016 (UTC)

Archived discussion regarding WP:DATERANGE
For future reference, because I spent too long trying to find it, the discussion over data ranges was archived at: When discussions like that take place outside of the MOS talk pages, should a link not be left here in the archives after the discussion has concluded? Maybe I missed such a link. I did find a pointer to the discussion in these archives here, but nothing after the discussion closed. Oh. I've just seen the note added here. Managed to miss that somehow... I'll still leave this note here, in case that note gets removed at some point. Carcharoth (talk) 06:15, 5 September 2016 (UTC)
 * Village pump (policy)/Archive 129

Wrong/contradictory examples for time durations in "Mixed units"
The table in MOS:NUM gives "1 hr 30 min 7 sec" as a correct example and "1 h 30 min 7 s" as an incorrect one, whereas the next section, MOS:NUM, clearly says that the correct symbols for hour, minute and second are "h", "min" and "s" respectively (it also does not mention "hr" and "sec" as correct, which probably implies that they are at least not recommended, but in fact are incorrect according to SI rules). That is, "1 h 30 min 7 s" is actually perfectly correct, and "1 hr 30 min 7 sec" is not SI-compliant and contradicts the rest of MOS:NUM ("hr" and "sec" are not mentioned anywhere else). — Mikhail Ryazanov (talk) 07:31, 27 August 2016 (UTC)
 * Some points:
 * Note that the Specific Units table explicitly endorses both min and m for minutes.
 * Wikipedia quite consciously is not always SI-compliant. As I recall (for example), SI doesn't recognize day as a unit of time, and we're certainly not going to tell editors they can't use that!
 * Clearly there's a discussion needed here, so let the games begin!  E Eng  07:44, 27 August 2016 (UTC)
 * I guess what the table is trying to say is that a mixed time should be internally consistent; choose the long abbreviations hr-min-sec or the short ones h-m-s but don't mix them. Kendall-K1 (talk) 14:21, 27 August 2016 (UTC)
 * I suppose is right about the intent of the table, but according to the SI brochure, hour and minute, while not SI units, are accepted for use with SI. The correct symbols, according to the brochure, are h and min. Using m as a symbol for minute is not especially desirable, because it could be confused with meter. So "min" is a suitable symbol to use together with "h" and "s". Jc3s5h (talk) 19:59, 27 August 2016 (UTC)
 * Yes, in theory it could be confused with the metre - but in context? I doubt it.  We do say already (in a different part of the text), "Use m for "minute" only where there is no danger of confusion with meter".


 * I just did a Google search for "hr", "min" and "sec" in Wikipedia, and this unit style seems to be used mostly for sports articles and early aviation records.


 * I don't see it as problematic to allow hr and sec to be used consistently with min in a mixed unit. YMMV, but I don't have the impression in particular  that h is common in English as a unit symbol for the hour, even if it is accepted by SI. Kahastok talk 20:30, 27 August 2016 (UTC)


 * I don't think it's common to use a unit symbol for hour in English at all. Time of day and duration in mixed units are usually expressed just with a colon (or, if seconds are included, a colon between hours and minutes, and a second colon between minutes and seconds). For example, the various English language formats for time of day or duration in Excel all use colons. I think most other ways of writing durations in short form would be found in scientific and technical work, and would thus lean toward following the SI brochure. Jc3s5h (talk) 21:13, 27 August 2016 (UTC)


 * I agree that 1:30:07 is the most accepted and probably the best format, but my point is that giving "1 h 30 min 7 s" as unacceptable while "1 hr 30 min 7 sec" as acceptable looks really wrong and inconsistent. Regarding the usage, "h" is used, but I have also seen idiotic examples like "2 hrs." ("idiotic" because "2 hours" is much more readable and only slightly longer, and if those people wanted a shorter form, then it should be "2 h", which is even shorter and actually standard). As I understand, WP:MOS is supposed not to invent its own rules but to combine the existing ones in a consistent manner. From this perspective, "h", "min" and "s" (and, regarding EEng's comment, "d" for "day") are codified by BIPM and NIST, but I haven't seen any style guide prescribing to use "hr" for "hour" (I also suspect that if these are considered as abbreviations rather than symbols, then at least "min." and "sec." should have periods). — Mikhail Ryazanov (talk) 02:49, 28 August 2016 (UTC)

I did some search through the history, and it seems that previously "1 h 30 min" was actually listed as an acceptable example. Then these "hr" and "sec" were added by  without any references. Then made  the current version after some discussion  among him(her)self... :–) Frankly, I could not understand how "1 h 30 min" became unacceptable, neither I could find any justification for "hr" and "sec". It was also mentioned in that discussion that "1h 23m 45s" is used for astronomy and navigation, but "1 h 30 m 7 s" seems to be just made up. So, unless somebody can provide reliable sources advocating these notations ("hr", "sec", and "m" for minutes) or rational arguments why we should keep them here, I would suggest to move them to "unacceptable" and return "1 h 30 min 7 s" to "acceptable" in order to make this MOS self-consistent and consistent with the BIPM/NIST notation. — Mikhail Ryazanov (talk) 08:33, 29 August 2016 (UTC)


 * Not to make excuses, but at that time "we" (I and some others) were reorganizing this page, with the intention of improving the presentation without changing the substance. This would be one of the few edits which did more than reformat/reword existing examples. I notice that around that time I also did this so I'm pringing  to see if he remembers anything about this. It's also possible there was some Talk traffic on the subject too.


 * While Wikipedia's MOS generally borrows from styles used and seen elsewhere, it adapts, modifies, and extends to suit its own needs, and it certainly isn't bound by RS the way article content is.  E Eng  03:33, 30 August 2016 (UTC)
 * Certainly min and sec can't be mixed. It's min and s, or minute and second. Tony   (talk)  08:37, 30 August 2016 (UTC)
 * I agree with Tony, and (contradicting Eeng) would add day (symbol d) to the list. I see no need (ever) on wp for the abbreviations "sec" and "hr" (yuk!). Dondervogel 2 (talk) 09:11, 30 August 2016 (UTC)
 * I'm happy to be the scapegoat if it helps us toward a better guideline, but how does adding d contradict me?  E Eng  09:38, 30 August 2016 (UTC)
 * Aren't ' and " the usual abbreviations for minutes and seconds? Hawkeye7 (talk) 09:59, 30 August 2016 (UTC)
 * These are widely used in other contexts, so we do not allow them to be used for units of time (or for feet and inches). Instead, they are used (or more correctly, the single and double prime are used) only for minutes and seconds of arc. See the "Specific units" table under "Angle".


 * My thoughts are to deprecate the nonstandard symbols "hr" and "sec" and to require the use of "h" and "s" as symbols for the units of time; "d" for day may also be acceptable. The use of "m" to denote the minute should be strongly discouraged. In short, I agree with Mikhail Ryazanov. Archon 2488 (talk) 11:39, 30 August 2016 (UTC)

Proposal T1
So, since no new thoughts appeared here in the passed week, and most editors seem to agree with my concerns, here are the proposed changes:

I think, adding day (d) to the last table is not necessary, since that "table lists only units that need special attention", and I cannot imagine what wrong can happen with it. — Mikhail Ryazanov (talk) 00:13, 6 September 2016 (UTC)


 * To summarize the changes:
 * In the first table, 1 hr 30 min 7 sec is moving from Acceptable to Unacceptable
 * In the first table, 1 h 30 m 7 s is moving from Acceptable to Unacceptable
 * In the first table, 1 h 30 min 7 s is moving from Unacceptable to Acceptable
 * In the first table, 1 hr 30 m 7 sec is moving from Unacceptable to nowhere
 * In the second table, you're dropping the note text, Use m for "minute" only where there is no danger of confusion with meter
 * In the second table, you're dropping everything about years


 * OK, everyone... thoughts?  E Eng  01:20, 6 September 2016 (UTC) , did you really mean to drop the material in the second table about years?
 * I only included changes related to hours–minutes–seconds. Everything about years and the rest in these tables stays as it is. — Mikhail Ryazanov (talk) 01:28, 6 September 2016 (UTC)
 * OK, I added the years stuff to the second table so that it's clear it's not being changed or removed.  E Eng  02:35, 6 September 2016 (UTC)


 * Looks good to me. Tony   (talk)  03:34, 6 September 2016 (UTC)


 * Sorry for the absence. This proposal looks good to me, too.  —sroc &#x1F4AC; 11:12, 15 September 2016 (UTC)


 * I've installed version T1 in the live guideline.  E Eng  03:12, 28 September 2016 (UTC)

Guidance on mid-2000 or mid 2000
Is it or ? Similarly for early-2000 and late-2000. I could not see this issue covered in the style manual. Perhaps someone could decide which form is acceptable and add this information to the guide. Best wishes. RobbieIanMorrison (talk) 23:53, 23 September 2016 (UTC)
 * Context, please?  E Eng  00:10, 24 September 2016 (UTC)

Following similar usage elsewhere, Robbie, the answer is both, as you might have guessed. Mid-2000 only when the pair are used together as an adjective. So we might write: "We should be done by mid 2000." But we also could write: "We're not sure we'll be able to meet the mid-2000 deadline." It would be exactly the same if we instead used "the middle of." So we might write: "We should be done by the middle of 2000." But we also could write: "We're not sure we'll be able to meet the middle-of-2000 deadline." Wikifan2744 (talk) 04:05, 2 October 2016 (UTC)

Commas instead of Periods as decimal separators
For a website which is global, shouldn't acceptance of both Latin and Arabic numeral systems be equally acceptable? One such example is the 2016 Central Italy earthquake article, where in the talk page it was noted an editor used a comma and not a period. Considering most of Europe and over half of the world use the Arabic comma separator, it just seems that in some circumstances, such as this about an Italian event, systems of the locality should be used, as is the case with spelling differences between American and English when talking specifically about a country-related topic.Grez868 (talk) 00:41, 28 August 2016 (UTC)
 * Italian usage has no weight here, because this is the English Wikipedia, and in the 21st-c English-speaking world the period/full stop are overwhelmingly the decimal separator, though there are minor exceptions.  E Eng  01:51, 28 August 2016 (UTC)
 * The English language version of Wikipedia is a worldwide encyclopedia for people who speak English, which is why spelling variations are accepted. Of course, English Wikipedia is read and edited by people who are not fluent in English and I welcome this. I think a fundamental principle behind Wikipedia is, however, to have versions of articles in all languages but delivered as separate language works using separate local cultural styles. This should hopefully reduce the disadvantages faced by people, who are not fluent in English, when they wish to access knowledge. I think a major objective of Wikipedia is to not force people to read only the English version of Wikipedia. An Italian person should be able to read a high-quality article about DNA in Italian Wikipedia using their native language and familiar notation. I think Wikipedia is about recording the knowledge of all cultures but that's not the same as having to present it in all formats in a single work (English Wikipedia). I think it is not unreasonable for English Wikipedia to adopt the decimal (and other) notation used in English-speaking countries. I wouldn't go to Italian Wikipedia and confuse readers by using a decimal point instead of the decimal comma that is used by Italians. It's also problematic for the thousands separator. One million is usually written as 1,000,000 in English-speaking countries but can be written as 1 000 000 in Poland but 1 000 000 or 1.000.000 in Germany. Similar issues are linked to e.g. quotation marks, which vary from country to country even more than decimal notation. I think the solution to this issue probably involves improving the content of Wikipedias in other languages rather than making English Wikipedia even more dominant while the other Wikipedias fall into disuse and force everyone to use English. GeoWriter (talk) 12:07, 28 August 2016 (UTC)
 * "which is why spelling variations are accepted"—yes, standard varieties within the anglophone world. I used to think it was a little racist, but in reality it's because standard varieties are the most accessible, in the larger scheme, by second-language speakers who read en.WP. Now, comma and point reversals spin out anglophones' minds, my own included: you have to stop a little to process it, and many readers will be foxed by it if they don't know. I'm afraid the comma–point usage is hardwired into the language, just like not writing 445 €, which is really annoying and has to be corrected frequently. I understand where you're coming from, but English is English, and we're stuck with it as part of the translation task. Tony   (talk)  12:15, 28 August 2016 (UTC)


 * My personal philosophy here would be to pick one and stick with it; since English typically uses the period as a decimal separator, that is what en.wp uses. Personally, I am opposed to using commas in numbers at all because of this ambiguity; the SI standard, for example, is to permit either the comma or the period as a decimal separator, so long as one of them is used consistently (BIPM publications in French use the former, while in English they use the latter), while large numbers should be split up with thin non-line-breaking spaces to avoid ambiguity: 10 590. Formally, "10,590 km", "10.590 km", and "10 590" mean exactly the same thing. Archon 2488 (talk) 15:08, 28 August 2016 (UTC)
 * GeoWriter says "I wouldn't go to Italian Wikipedia and confuse readers by using a decimal point instead of the decimal comma that is used by Italians." I don't understand. GeoWriter has just argued for using the typography local to what the article is about -- Italian notation for an earthquake in Italy is the example. Wouldn't an article about an American earthquake in the Italian Wikipedia then use the American decimal point by this logic? This doesn't make sense, so I suspect is some kind of special pleading along and so I've lost interest in the proposal. Herostratus (talk) 15:38, 28 August 2016 (UTC)
 * Did you mean to position this as a response to me? I am confused. On my reading of GeoWriter's comment above, it does not mean what you say it means. Rather, GeoWriter says explicitly that "...it is not unreasonable for English Wikipedia to adopt the decimal (and other) notation used in English-speaking countries." He does not say that the English WP should use Italian notation or that the Italian WP would be expected to use American notation (rather the opposite), and he does not use the phrasing "local to what the article is about" – I would be cautious about paraphrasing people in this way unless you can be confident of their intended meaning. I am, however, confused by his closing remarks about improving non-English wikipedias vs. "making English Wikipedia even more dominant". I don't understand what this has to do with typographical matters. Archon 2488 (talk) 15:55, 28 August 2016 (UTC)
 * Herostratus wrote: "GeoWriter has just argued for using the typography local to what the article is about -- Italian notation for an earthquake in Italy is the example." That is not my position. My position is: use English notation on English Wikipedia and Italian notation on Italian Wikipedia. Perhaps you have mistaken me for another contributor, because I think your comments about what you think I've said seem to more closely reflect the proposal made by Grez868 who started this discussion. GeoWriter (talk) 16:24, 28 August 2016 (UTC)
 * Oops sorry you're write I misread it. Herostratus (talk) 21:56, 28 August 2016 (UTC)
 * It was hard to see what Grez868 was getting at, with his Arabic versus Latin concept. I thought he meant Roman numerals at first.  We all use Arabic digits, but the separator conventions do not come from there.  In the English encyclopedia, we use point for decimals and commas (optionally) for digit grouping; mixing these up in different articles would be a disaster for our readers, so we don't.  Dicklyon (talk) 16:30, 28 August 2016 (UTC)
 * And I agree with Archon that the optional use of commas to group digits is a bad idea and introduces ambiguity for those who sometimes interpret the comma as a decimal point; the BIPM says not to do this, yet WP allows it. If anything, we should be moving toward stricter, more uniform, more standard, less ambiguous number styling, not toward more ambiguous as Grez868 proposes here.  Dicklyon (talk) 16:36, 28 August 2016 (UTC)
 * Archon 2488, I think many non-native speakers of English contribute to English Wikipedia, even in preference to their native language version, because English is the dominant Wikipedia version. I welcome these editors. I think improving non-English Wikipedias to address the dominance of English Wikipedia is relevant to typography and notation because I think it is a contributory reason why e.g. decimal commas occur on English Wikipedia. GeoWriter (talk) 17:23, 28 August 2016 (UTC)
 * I understand what you're saying, but the solution here at en.wp is to create a consistent style and require editors to stick to it (and you don't seem to disagree with this). We need to bear in mind that, although its servers are based in the USA, WP is an international project with a global scope, and we would like our content to be equally accessible (as far as that is possible) to everyone – so we cannot just follow the Associated Press Stylebook (for example). We need to accept that a very large proportion of our readers and editors are not native English speakers, and so our notation should be as close to a standard international style as possible (while not totally disregarding Anglosphere norms); this is why I say that commas in numbers should not be used, since they can cause confusion with the decimal separator widely used in non-Anglophone cultures (and using the comma as a decimal separator, conversely, confuses Anglophones).


 * Of course, the need for global reach is also why we have wikiprojects in languages other than English – but clearly, we are not capable of implementing solutions that would require enormous editor-power to make every version of WP of roughly equivalent quality. If your native language is Greek or Latvian, you're probably resigned to the fact that you can get access to a lot more information in English than in your native language (there are concepts in statistics and economics that explain the emergence of such monopolies), and realistically, nothing we do at Wikipedia is going to change that, because the reasons why it happens extend far beyond the scope of Wikipedia. Archon 2488 (talk) 12:05, 29 August 2016 (UTC)


 * I think you actually raise a very good point there. Often times when searching for something in another language, the content of the page is close to nothing compared to what is on the English version. Infoboxes are sparsely used and only pushes everyone to the English Wikipedia. After reading all the views here, I have to conclude that (personally), I agree that there should be a single international convention developed where separators are used only when actually speaking of a decimal integer where a period (".") is necessary and spacing should then be used for other extended integers. For an international project where English is obviously the most used, it just seems this would be the thing to cause least confusion to the reader-base as an entirety, and using spaces in lieu of decimal commas/points would be obvious to everybody, even when a decimal point is used to indicate a number with decimal places/fractional numbers. It's the same with commas as separators of large numbers (i.e. 1,001). Someone in Germany would read this as 1.001 (a number with three decimal places), whereas some countries (even English speaking) would be confused as to why there is even a comma there. I for one in School in the UK was never taught to use a comma for 4 digit numbers, only for 5 and above. The system, as-is, is a farce for the international audience and isn't working by the number of edits which have to take place to correct them.Grez868 (talk) 22:31, 3 September 2016 (UTC)


 * Um, would I be right in summarizing the above as: Everyone except the OP agrees we should retain the current guideline i.e.
 * A period/full point, a comma, is used as the decimal point (6.57, not 6,57).
 *  E Eng  19:55, 28 August 2016 (UTC)
 * Yes. Kendall-K1 (talk) 20:04, 28 August 2016 (UTC)
 * Yes. Peter coxhead (talk) 12:32, 29 August 2016 (UTC)
 * Yes. Robevans123 (talk) 14:41, 29 August 2016 (UTC)
 * Me too. The important principle here is adopt a rule and stick with it, consistently. One can argue about whether that rule should be a period or full stop, but a comma? Not on the English wp  Dondervogel 2 (talk) 22:18, 29 August 2016 (UTC)
 * Me too (in case it wasn't clear). We haven't heard from the OP since he/she OP'd, so I think this is dead anyway.  E Eng  00:09, 30 August 2016 (UTC)
 * Yes. By the way, I have seen a script change the dot to a comma in "9.999" where 9 is any digit. It even changed 0.342 to 0,342! That's on the principle that someone must have copied the number from another wiki where dot is a thousands separator. Johnuniq (talk) 01:32, 30 August 2016 (UTC)
 * On the contrary, there are comments saying that "something" needs to change to achieve better standardisation and cause less confusion amongst the readerbase as a whole, especially considering how many of them are not native to the UK/USA. Read my comment above for more on what I think.Grez868 (talk) 22:31, 3 September 2016 (UTC)
 * What I see are concerns that the "thousands separator" (shall we call it) should be a space/thinspace instead of comma. I see no one (including you) advocating any change to the bit of guideline text I quoted above.  E Eng  23:00, 3 September 2016 (UTC)
 * To be honest, I'm a little confused myself right now whether i meant that percentile numbers should be adjusted or numbers depicting large numbers as the word decimal covers all forms of number which we actively use (alternatives being of course Binary, Octa and Hex). I tried finding my original logic by looking through the edits of the initially mentioned article but can't seem to find it. Timestamp of my original post for me is a little after midnight, August 24th (UTC) but the article wasn't started until hours after that. In any case, both scenarios could be cleared up by only having one punctuation used in numbers of all kinds, because doing so would eliminate any cause for confusion of what it is (a percentile/number with decimal point or a long integer). As aforementioned, this would be done by eliminating commas from long integers. I guess this suggestion is an unlikely one though because reflecting, with the number of articles we have on the English side of Wikipedia, adjusting as necessary would literally take forever. I'm with the consensus.Grez868 (talk) 23:44, 3 September 2016 (UTC)


 * We should stick with the dot as the decimal separator. This is English, not French or whatever Wikipedia. Something like "47.5" is read aloud as "forty-seven point five" because English uses a point here, not a comma.   — SMcCandlish ☺ ☏ ¢ ≽ʌⱷ҅ᴥⱷʌ≼  18:46, 8 September 2016 (UTC)

Looks like we're done re . as decimal point; now what about the thousands separator?
I would support the deprecation of the comma as a thousands separator. It would need to take forever to implement (that's what bots are for) but even if takes a long time, it's still worth making this improvement. Isn't that what the thin space is for? Dondervogel 2 (talk) 15:51, 5 September 2016 (UTC)
 * Well, if you guys want to take on convincing people to deprecate comma, I'll enjoy the show, but no matter what this should not be a bot-implemented mass change. Aside from the problem of subtle errors of some kind (imagine an article on IBM data formats) for people who will be suspicious in the first place that the thinspaces are some kind of internationalist commie politically correct typographical plot, nothing will be more infuriating than a bot arriving to implement it automatically. Take the Fabian approach.  E  Eng  18:14, 5 September 2016 (UTC)
 * Happy to defer to EEng's greater wisdom re Pasionariabot ( sincerely meant - no sarcasm intended, honest guv ). My preference for the thin space over the comma remains. Dondervogel 2 (talk) 18:23, 5 September 2016 (UTC)
 * While some scientific topics are exceptions, there is no prospect of replacing commas with gaps generally. Anyone wanting to make that proposal should work out how to deal with the wikitext and the copy-paste problem. Try copying the following text and pasting it somewhere:
 * → 1,234,567
 * → 1 234 567
 * → 1&thinsp;234&thinsp;567
 * The first and second lines can be copied/pasted as expected, but the third line does not give a useful number. Very few enwiki editors would want to use anything other than 1,234,567 and would not want to use gaps or other klunkiness. Johnuniq (talk) 01:15, 6 September 2016 (UTC)
 * I agree that the potential advantages of deprecating, as thousands separator aren't worth the trouble. This people can live with.  E Eng  07:39, 7 September 2016 (UTC)
 * Notwithstanding my preference for the thin space, I agree we can live with comma. Dondervogel 2 (talk) 11:42, 7 September 2016 (UTC)
 * The thousands separator has been a mess in the world of computers at least since the time we stopped printing on 14 inch (35 cm) wide green bar paper with tractor-feed holes, and expected ordinary people to read numbers produced by a computer. The computer industry is nowhere close to solving the problem, and I don't think Wikipedia is in any position to fix it. Lets just curse under our breath and stick with commas. Jc3s5h (talk) 13:07, 7 September 2016 (UTC)
 * Stick with somma. Using a space of some width or other is a non-English and (in English) specialist usage that is unrecognized by and confusing to the majority of our readers.  — SMcCandlish ☺ ☏ ¢ ≽ʌⱷ҅ᴥⱷʌ≼  18:47, 8 September 2016 (UTC)


 * See right. But to be clear, though I think people would understand a thin space without problem, I agree we should leave this particular hornet's nest alone.  E Eng  21:35, 8 September 2016 (UTC)
 * The use of the space instead of the comma in numbers is official here in Australia, but I am concerned that the text on Wikipedia would wrap on the space. Hawkeye7 (talk) 00:46, 3 October 2016 (UTC)

Range-dash wording
"(as is any range)", at the top, should be "(as is any range not preceded by "between" or "from")", if we're to be precise. Or otherwise reworded. Tony  (talk)  02:43, 25 September 2016 (UTC)
 *  E Eng  05:19, 25 September 2016 (UTC)
 * That looks good; thanks. I'm still thinking about the discussion, wherever it was, about digit elision in page number ranges.  We don't do this a lot, but a few editors and a few articles still do.  Seems to me we ought to recommend against digit elision as completely pointless and potentially confusing, and gradually work on fixing such things (as I've been doing for years anyway).  I don't see this as conflicting with the general tolerance of a wide range of citation styles. Dicklyon (talk) 01:03, 28 September 2016 (UTC)
 * In tables and infoboxes? I think four digits plus two is ideal for space-constrained contexts. Tony   (talk)  01:35, 28 September 2016 (UTC)
 * I think that has been taken care of. I'm talking about page ranges in citations.  Dicklyon (talk) 02:21, 28 September 2016 (UTC)


 * The Chicago Manual of Style seems to prefer the form with two digits for the end page. (Note, not just one, even if that would be enough.) I have a request in for the Modern Language Association, as their guide isn't online. Since reference page ranges tend to be in the low tens of pages, for either whole journal articles, or sections of books, the shorter form seems fine to me. For other than page ranges, I don't know that anyone is suggesting it.  Gah4 (talk) 03:04, 28 September 2016 (UTC)


 * User:Dicklyon, you really prefer pp. 12,344–12,346 to pp. 12,344–46? You get these massive numbers in cumulatively paginated journals—a great disservice to everyone. Tony   (talk)  06:54, 2 October 2016 (UTC)
 * I have not encountered those. And I'd leave out the commas. Dicklyon (talk) 01:35, 3 October 2016 (UTC)

What should the articles (on the topic of years) from 1 to 100 be moved to?
Please comment at the follow-up RfC on how the topic of years 1-100 should be titled here. Thank you, — Andy W.  ( talk  · ctb) 00:21, 6 October 2016 (UTC)
 * Just when you thought it was safe to go back in the water...  E Eng  00:26, 6 October 2016 (UTC)

Hex notation when there is a standard
From MOS:HEX, you are supposed to use C (0x) notation. Is this still true when there is a standard notation for hex constants in the case that the article is describing? The current discussion is on UTF-32, where Unicode normally uses the U+ notation. Also, in discussions for machines that have an assembler notation for hex constants, it makes sense to me to use that notation. Gah4 (talk) 02:21, 6 October 2016 (UTC)


 * MOS is wonderful, but it's only a guideline and should not be rigidly enforced without thought. The problem appears to be an IP at Talk:UTF-32 and their opinion about 0x000000 being the correct way to write 0 is misguided. Of course the article should use Unicode procedures, after a brief explanation. Johnuniq (talk) 02:30, 6 October 2016 (UTC)


 * In the current UTF-32 case, I think I am with the 0x0000 form, as it seems more consistent to use the same notation at both ends of a range. If I am initializing an array in C, I use the same notation for all elements, even zero. Otherwise, most likely just zero. But in this case, I suspect that the U+ notation is an even better choice. Gah4 (talk) 03:05, 6 October 2016 (UTC)


 * How about: In computer-related articles, unless there is a strong reason for another notation, use the C programming language prefixes ...? Gah4 (talk) 03:09, 6 October 2016 (UTC)

What is correct? 23rd or Twenty-third?
Hello. Can anyone let me know what is the correct MoS if we have to write twenty-third in articles - "23rd" or "twenty-third"? I am asking in connection with this edit. Thanks, Arun Kumar SINGH (Talk)  16:25, 6 October 2016 (UTC)
 * My reading of the MOS is that either is acceptable in this case as long as both numbers are in the same style. The ordinal suffix should not be superscripted. Kendall-K1 (talk) 16:31, 6 October 2016 (UTC)
 * Mine too but it is not clearly defined (unless I missed it). Arun Kumar SINGH (Talk)  16:32, 6 October 2016 (UTC)


 * I've boldly added something to MOSDATES which I think will help.  E  Eng  18:46, 6 October 2016 (UTC)
 * My understanding from previous discussions (admittedly shooting from the hip here as I have not checked the present text) is that "23rd" is never correct. Only "23rd" and "twenty-third" are permitted, right? Dondervogel 2 (talk) 21:19, 6 October 2016 (UTC)
 * Yes. It's all in the section diffed at the link I just gave (including the link given there).  E Eng  21:24, 6 October 2016 (UTC)
 * I did not find the clarification in the linked text so I read it again ... and again ... and again ... and would have continued ad nauseum had I not thought of ignoring the link and just reading the line AFTER it. My suggestion to avoid trapping our readers in the same infinite loop is to move the link one line down, as edited a couple of minutes ago. Does that work? Dondervogel 2 (talk) 00:22, 7 October 2016 (UTC)
 * Good idea. Good idea. Good idea. Good idea. Good idea. Good idea. Good idea.   E  Eng  00:30, 7 October 2016 (UTC)

hex range
As noted, hex values use C notation for hex constants. The question now is a range of hex values. Should all number in a range use the same base? (Seems obvious.) Should they even if one is zero? (Less obvious.) As an example, consider the range of non-negative 32 bit twos complement values: 0x00000000 to 0x7fffffff. It is convenient in some cases to indicate the width (32 bits in this case) with the appropriate number of leading zeros, or all zeros in the zero case. But one could also just use 0 for zero, or 0x0. There is an edit war regarding this, so any help would be appreciated. Gah4 (talk) 21:30, 12 October 2016 (UTC)


 * I'm sorry there's an edit war, but this is far too obscure a case for MOS to get into, unless it's been coming up over and over. Where's the edit war?  E Eng  21:38, 12 October 2016 (UTC)


 * The specific case is for UTF-32. Gah4 (talk) 21:43, 12 October 2016 (UTC)
 * I took a look. This is definitely something that could be appropriate either way, "depending". You're gonna have to work it out on the talk page. (Of course, I invite any of my esteemed fellow editors stalking this page to help in that discussion if they feel qualified to do so.)  E Eng  21:46, 12 October 2016 (UTC)
 * It's lamer than usual, and I agree it needs use of the article talk page, not MOS. At UTF-32 one tribe wants to change things like to . Another issue is whether to use  (or U+00000000 and U+7FFFFFFF). Johnuniq (talk) 21:56, 12 October 2016 (UTC)

Era: "BCE" and "CE"

 * Heading was "Era:The time has come for Wikipedia to require that era designations, if used, must be "BCE" and "CE" in almost all new articles "

Increasingly, scholars using dates preceding the Christian era, and especially those working in fields such as archeology, Biblical studies, linguistics, and history, have recognized that the use of Christian date designations ("BC" and "AD"), in a world in which scholars and other educated persons increasingly come from the two-thirds of the world's population that is non Christian, is inappropriate, except, perhaps, in articles about Christianity itself or in those about the history of Christian parts of the world. Instead, the scholarly world is emphatically switching to the use of the nonsectarian date designations "BCE" and "CE" in the above fields and in science in general.

For example, the American Journal of Archaeology says: "The AJA uses B.C.E. (“before the common era”) and C.E. (“common era”) for historical dates." In other words, authors must use the nonsectarian style for era in manuscripts submitted to the AJA.

From previous discussions I know that some writers are quite adamant that our calendar is based on Christian events and that it is wrong to use anything but BC and AD. Many of us, however, agree with former United Nations Secretary-General Kofi Annan (himself a Christian) when, under "Rationale" in our article on "Common Era," he is quoted as having argued:

"[T]he Christian calendar no longer belongs exclusively to Christians. People of all faiths have taken to using it simply as a matter of convenience. There is so much interaction between people of different faiths and cultures – different civilizations, if you like – that some shared way of reckoning time is a necessity. And so the Christian Era has become the Common Era."

The English Wikipedia is falling behind the times and is beginning to look silly by continuing to allow authors to use BC and AD at their own discretion. Following the lead of the AJA (above), we would require articles on any subject to use BCE and CE. But the opposition to such a sudden and total change in policy would be huge. My recommendation, instead, is to allow existing articles to follow current guidelines. That would permit change to occur gradually and gently as editors replace BC and AD with BCE and CE when they discover existing articles where the continued use of BC and AD would be clearly inappropriate, such as articles about non-Christian parts of the world or articles about events prior to the common era that have no connection to Christianity, even if they occurred in parts of the world that are now largely Christian. Such change to BCE and CE would eventually include almost all existing articles that have no obvious connection to Christianity.

New articles, on the other hand, should be required to use BCE and CE, except, perhaps, for those specifically about Christianity or about the history of Christian parts of the world, where even science was intimately connected with the church (think Galileo Galilei). Such articles, some Wikipedians would argue, should reflect that connection to Christianity by the use of BC and AD. The AJA (above) would not allow it, but Wikipedia is not the AJA, and so we might have to — at least for a time.

I believe that this untenable situation needs to be remedied as soon as possible, not years from now. Continued procrastination will just lead to a further erosion of the already slipping reputation of Wikipedia as a reliable repository of information and knowledge from reputable and verifiable sources. Wikifan2744 (talk) 03:50, 2 October 2016 (UTC)


 * Per existing guidance Basically it doesn't make any sense to force this, one should follow what the sources for the topic of interest give, rather than forcing it. --M ASEM  (t) 04:03, 2 October 2016 (UTC)


 * Oppose Please, please let's not do this again.  E Eng  04:26, 2 October 2016 (UTC)

The alacrity of your response, Masem, makes it clear that you are one of those whose knee-jerk response I was anticipating in my third paragraph. It also makes clear that you didn't impartially consider the situation I described. Of course, BC/AD is traditional. The horse was traditional, too, but telling early adopters of the automobile to "get a horse" didn't make the automobile disappear.

The tide of publications, including major style guides, switching to BCE/CE has reached a tipping point. Such sudden, massive changes always take the unwary by surprise, forcing them to scramble to just keep up. Further, we have editors, Masem, who are so determined to keep BC/AD entrenched that they ignore the choice of the sources to use BCE/CE. They are the ones who are forcing it.

We have been following existing guidance and it's contributing to the English Wikipedia becoming a joke. Users reading about historical events in China with dates designated as AD can only laugh and go elsewhere for their info.

Irrational rearguard actions by stubborn and inflexible traditionalists are the norm when rational persons try to put things aright. In their efforts to stop the tide, however, they just make adaptation to the new circumstances increasingly more painful and costly to accomplish. Wikifan2744 (talk) 06:40, 2 October 2016 (UTC)
 * It's frustrating, but perhaps Masem's view is a reaction to the battleground of discussions about this issue. Me, I'd go with BCE and CE only, in a flash; but I'm not up for the monumental fight against the christian lobby. Tony   (talk)  06:50, 2 October 2016 (UTC)
 * English Wikipedia becoming a joke. Harbingers of doom rarely make a good case. --Izno (talk) 13:19, 2 October 2016 (UTC)
 * Like, I prefer BCE/CE, but should have more confidence in what they write: the tide of publications, including major style guides, switching to BCE/CE has reached a tipping point. If this is indeed so, editors will switch without needing to be forced. Peter coxhead (talk) 14:45, 2 October 2016 (UTC)
 * Great point.  E Eng  17:35, 2 October 2016 (UTC)


 * The horse was traditional, too, but telling early adopters of the automobile... Let me stop you there. No, you can't compare BC/AD vs. BCE/CE to horse vs. automobile. BCE/CE is, rather, still a horse, but one you've insisted on calling a "Common Riding Animal" while otherwise continuing to use in the exact same fashion, while also taking a conniption fit and employing a holier-than-thou and sanctimonious attitude toward those who still refer to it by the common terminology of "horse". I perceive morally-outraged BC/AD haters as no different than someone who might equally insist that we stop calling the fourth planet from the sun Mars because that planet "has nothing to do with Roman mythology". It's a laughably ridiculous attempt to control language. Many secular sources use BC/AD, while many others use BCE/CE. It varies wildly across countries using the English language. We should continue to use both for the exact same reasons we continue to employ WP:ENGVAR. BCE/CE are not increasingly used because they are any more "valid" or correct, but instead mostly due to modern sensibilities relating to political correctness, in a similar vein to countless other terms that have developed since the 1980s. For as long as BC/AD are used by reliable sources to refer to the era in which they were the originally-employed terms, we will use them. To artificially force their deletion here would be ridiculous. If you don't like the de facto use of the Christian calendar, start lobbying for the Holocene calendar. —  Crumpled Fire   • contribs • 00:04, 3 October 2016 (UTC)
 * The Quakers (nice people they, except of course for Richard Nixon) for a long time refused to say, "Monday, Tuesday, Wednesday..." or "January, February, March..." because of their pagan meanings; for decades the venerable Bradshaw's Guide would tell you that a certain train did not run "on First Day in Fifth and Sixth Month", because George Bradshaw was a Quaker. But as nicely expressed here, "In the 20th Century, many Friends began accepting use of the common date names, feeling that any pagan meaning has been forgotten." That's a sensible, practical attitude of the sort reflected in our current guideline.  E Eng  00:18, 3 October 2016 (UTC)
 * While our sources may use BCE/CE due to "modern sensibilities relating to political correctness", we have the additional requirement for WP:NPOV, which is one of our core policies. WP:ENGVAR upholds WP:NPOV, but using BC and AD goes against it. Hawkeye7 (talk) 00:39, 3 October 2016 (UTC)
 * Okay, here we go with the NPOV argument. If you're going to take WP:NPOV to mean not using terminology that is etymologically tied to one religion over others, which is not at all what a proper reading of it would indicate, then you're gonna have a bad time with the English language itself (re: Christianity, and various European polytheistic religions). Additionally, I could easily argue that BCE/CE would constitute more of a violation of WP:NPOV than BC/AD do, since they specifically designate the Western Christian era as what should be considered the world's "common" era above all others, rather than simply employing the inherent terms originally associated with the calendar itself. The actual bias here is using the Gregorian calendar itself as our de facto calendar; the subsequent era terminology that is used is inconsequential. But alas, using the Gregorian calendar is just a condition of the world we live in. So is, by the way, using the Hindu-Arabic numeral system instead of Roman numerals, despite the latter's stronger initial ties to the West. Should we refer to them as Common Numerals and rid Wikipedia of all reference to "Hindu" in regard to these numerals to get rid of that pesky religious "POV"? Please, spare me. —  Crumpled Fire   • contribs • 01:15, 3 October 2016 (UTC)
 * Oppose - per EEng, let's not do this again. The trend is toward BCE, but BC is still by far more common. If anything, the current guideline is too generous in allowing the use of BCE in non-specialty articles. Let's re-visit this discussion when BCE is more common. Kendall-K1 (talk) 01:36, 3 October 2016 (UTC)
 * Oppose - per EEng. It's quite a timesink. Let's look at it again in ten years or so. Herostratus (talk) 14:58, 3 October 2016 (UTC)
 * And, you know, re "I'm not up for the monumental fight against the christian lobby" and so forth: grrr. For my money, BCE overly exalts the importance of Christ and here's why: "BC" means -- "Before Christ, which is basically a random date -- we could have had "From the Founding of Rome" or "From the Founding of the Shang Dynasty" or whatever; but some dude got lucky and here we are" whereas "Before the Common Era" seems to mean (or certainly could be taken to mean) "Before the Beginning of History". What else is "Common Era" supposed to mean? This equates the (supposed) birth year of Christ with the beginning of History or Real Life or The Age of the Common Man or whatever it's supposed to mean, and that's a bit rich for my taste. Herostratus (talk) 22:36, 3 October 2016 (UTC)
 * Indeed I find it hilarious the argument that those who use or support any continued use of BC/AD must be part of some "Christian lobby"... are those who have no desire to rename Mars to Common Planet Four also part of a pagan lobby? And notice today's Google Doodle about the 434th Anniversary of the Gregorian Calendar, right there in the official text it uses "BC" not "BCE". Is Google, a largely secular liberal organization founded by two American Jews, part of the "Christian lobby"? —  Crumpled Fire   • contribs • 14:30, 4 October 2016 (UTC)
 * Oppose - If and when BCE/CE becomes the more common usage, then (and only then) we might want to change our policy to favor BCE/CE. As it is BC/CE is still far more common, and far far more broadly understood (which would in fact be a reasonable argument for mandating the opposite policy from that being proposed). Paul August &#9742; 16:09, 3 October 2016 (UTC)
 * Oppose - It really doesn't matter, BC - Before Christ, BCE - Bell Canada Enterprises, CE - Conformité Européenne, whatever. It really doesn't make any significant difference.
 * I personally prefer the ISO 8601 date format, which is totally irreligious, non-culture specific, and non-ambiguous. Years prior to year zero are represented by negative numbers and years after year zero by positive numbers. Year zero, which Jesus Christ was not born in, is year 0. We should avoid building cultural and religious biases into standards.RockyMtnGuy (talk) 14:20, 4 October 2016 (UTC)
 * As well as I know, the usual system does not include a year zero, as zero hadn't yet been invented. Are any events known accurately enough that adding a year zero would require any changes?  As well as I know, there is at least a few year uncertainty as to the actual year that JC was born. (No birth certificate has been presented.) Even so, as far as I know it isn't up to Wikipedia to change the calendar system for the world.  I do agree that it makes some sense, though. Gah4 (talk) 16:33, 6 October 2016 (UTC)
 * There are many events before 1 January 1 that are known with an uncertainty of a few days, in terms of being able to convert the calendar in which they were recorded to a modern calendar. One example is the Assassination of Julius Caesar. Astronomical events before 1 January 1 can be dated with an accuracy considerably better than 1 day. Jc3s5h (talk) 17:06, 6 October 2016 (UTC)
 * I wasn't trying to be too serious about it, but it is interesting. I am sure that the astronomers could figure out the change, they already have to compensate when there is a leap second. I was thinking about all the already printed books that would have to be changed. If someone really wanted to do it, it could have been done along with the change to BCE. That is, an offset of 1 between BC and BCE. Then no change to old records would be needed. Too late for that now. Gah4 (talk) 17:22, 6 October 2016 (UTC)
 * Seems to me that BC and BCE are interchangeable enough not to bother anyone, so I Oppose requiring BCE. Is there something weaker than require, but that hints that one might be preferred? Seems that most people omit the AD or CE, but in case one did want to specify, I believe that CE makes enough more sense. I would require CE over AD. Gah4 (talk) 23:01, 3 October 2016 (UTC)

An Alternative Proposal
I agree with the vast majority of commentators above: we should not ban BC and AD. However, I feel we should encourage BCE and use CE where appropriate. I also feel that the present policy needs revising.
 * AD and BC are inappropriate in dealing with articles about non-Christian religions.
 * According to scholars, Jesus was born somewhere between 6 and 4 BCE. Therefore the traditional appellation makes no sense historically or theologically.
 * The traditional appellation is increasingly being replaced by CE/BCE.
 * Nevertheless, the traditional BC/AD usage is still very common and has strong support.

The present text reads:


 * BC and AD are the traditional ways of designating eras. BCE and CE are common in some scholarly texts and in certain topic areas. Either convention may be appropriate for use in Wikipedia articles.

I believe that something like this would be more appropriate. Note, however, this proposal leaves unchanged the proviso that the era style can only be changed by agreement:


 * BC and AD are the traditional ways of designating eras but BCE and CE are common in scholarly texts and are more appropriate in certain topic areas. However, BC/AD may be used in Wikipedia articles where its use is accepted.

This proposal may need rewording, but would something like this be more appropriate than the present text? Michael Glass (talk) 02:01, 16 October 2016 (UTC)


 * I have a better idea: stop talking about this and go back to improving articles. I see no evidence any change to the guideline is needed, or even desirable.  E Eng  02:27, 16 October 2016 (UTC)


 * No. All you've done is changed the wording from neutral to biased in favor of BCE/CE, with no credible reason. Why is it “inappropriate in dealing with articles about non-Christian religions” or “more appropriate in certain topic areas”, and who decides that? That's a rather vague and unfounded statement. Should Hindu-Arabic numerals only be referred to as such in articles relating to Arabia or Hinduism? Should "Mars" never be used to refer to the fourth planet from our Sun in articles about Christianity, Judaism, Islam, etc. because the god Mars isn't an Abrahamic deity? How about Mon­day, Tues­day, Wednes­day, Thurs­day, Fri­day, Satur­day? The Christian world kept those pagan names, why does the post-Christian world have such an itchy trigger finger for the sole Christian element of the calendar? Despite the BCE/CE euphemism's increase in popularity since the 1980s, it's still not more widespread than BC/AD. If it ever becomes overwhelmingly predominant, only then would preferring it here be appropriate to reflect the world at large. Until then, community consensus on an individual article basis is the best way to deal with this mess. —  Crumpled Fire   • contribs • 06:05, 16 October 2016 (UTC)

The responses above show that BC/AD has strong support. However, it is a mistake to consider Wikipedia as a "Christian world." Rather, it's a place that should embrace all, whether Christian or non-Christian. Nor should it be thought that all Christians are hostile towards BCE/CE.


 * Here is an argument for change from a Christian website


 * Here is the article on the Religious Tolerance website


 * Here is an article from the New York Times

However, this is not the main point. There are situations where the traditional BC/AD usage is not as appropriate as BCE/CE. Take the Wikipedia article on | Judas Maccabeus, or for that matter, | Moses where there were 13 BCEs in the text and only one BC. Whatever the wording, it should not imply that BC/AD and BCE/CE are essentially interchangeable in every context. They are not. Michael Glass (talk) 12:19, 16 October 2016 (UTC)