Wikipedia:Redirects are costly

Because of the vagaries of any language, and the multitude of topics that don't have an actual page, there is a need for redirects. These are handy pages that allow readers and editors to quickly get to a page that they are trying to find. But there are some redirects that can be more of a burden than a boon to Wikipedia.

Server space and bandwidth are cheap
According to WP:RFD: "deleting redirects is […] cheap because recording the deletion takes up little storage space and uses very little bandwidth. There is no harm in deleting problematic redirects."

Editors wanting to keep or delete a redirect must weigh the trade-offs. It is obvious in many cases whether deletion or retention is the correct option, so we have to decide on the ones in the middle – the grey area that is discussed at WP:RFD.

Since server space and bandwidth are not arguments for deleting or retaining a redirect, we have to give other reasons.

Redirects sometimes need to be updated as articles change
A redirect may be appropriate now only to become problematic later in the course of the growth of the encyclopedia. For example, if a new article is created that could be seen as a likely target of the redirect. Or whenever there is a change in the topic structure—when content is moved from one article into another, when one article is split into two, when an article is moved to or away from a primary title. In these cases, redirects could end up pointing to the wrong targets, so generally all incoming redirects need to be examined to see if any need retargeting. This is a laborious task if there are many of them, but also one that is not always performed.

Therefore, there should be as many redirects as are needed to guide readers to what they are looking for, but not more than that.

Redirects need looking after
Just like articles, redirects can see unhelpful edits: they can get vandalised, expanded into content forks, or retargeted to less suitable articles. Most redirects have few or no watchers at all, so such disruptive edits are likely to remain unnoticed for some time.

Incoming traffic is cheap
One valid reason for retaining an older redirect is that it is linked to from outside Wikipedia. This is particularly likely to happen if a redirect has been on Wikipedia for some time, as editors of other websites may have used either the original page name prior to a page move or have themselves used the redirect page name for other reasons. If the incoming traffic is large, it is always appropriate to keep it. ("Large" is a subjective term.) WP:RFD lists incoming links as a good reason not to delete a redirect.

A redirect that has other wikipages linked to it is not necessarily a good reason for keeping it. Current internal wikilinks can be updated to point to the current title. However, updating the current versions of articles and then deleting the redirect will break all the prior versions, which can be inconvenient for people looking at prior versions, reading old discussions, etc.

Sending redirects to RFD is costly
The mere fact that a redirect is listed and discussed at the Redirects for discussion page creates work for others. Reducing the maintenance burden that is placed on the shoulders of Wikipedians is important. There is a huge backlog of tasks that need attention and Wikipedia is forever growing. This means that there are evermore existing articles needing the attention of editors, and we have no inkling of whether there will be a large enough pool of editors in the future.

You can reduce this burden by:
 * not creating redirects that are unlikely to be necessary, and
 * not sending redirects to RFD, unless there is a serious problem that can't be solved any other way (e.g., WP:BLP violations). This includes not listing redirects for deletion that you think are "unnecessary", or which could be solved through other methods (e.g., adding content to an article that explains why that redirect points to that page, or re-pointing the redirect to a more appropriate page).
 * keep an eye on RfDs that you have created and be prepared to close them early as speedy keep where applicable.

Some unneeded redirects
There is no need to redirect from:


 * Implausible typos. They are eligible for speedy deletion if recently created. Redirects from common typos, however, are encouraged.
 * Titles that have both a name and an abbreviation
 * Titles that mix English and another language, when the target title is monolingual
 * Titles with punctuation, obscure errors, additions, or removals that have no specific affinity to one title over any other:
 * e.g. being in quotations, having a period at the end, containing an added phrase that could describe most other articles, missing the first or last letter of a title (provided this is not a common mistake or typo regarding that specific word or term), or a disambiguated title with one parenthesis missing (the last is an example of an unnatural error; i.e. an error specific to Wikipedia titling conventions that would likely not be arrived at naturally by readers, thereby adding to the implausibility).
 * Titles with adjectives (e.g. important, significant, and consequential) that have no more affinity than any other for the subject at hand.
 * Errors in the act of disambiguation (a house-specific titling convention that should not be propagated incorrectly):
 * e.g. disambiguated titles with extra, missing, or misplaced spaces and brackets such as ( disambiguation), disambiguation), (disambiguation, ((disambiguation), and X(disambiguation); even more obscure errors like the wrong type of or mismatched brackets such as [disambiguation] and {disambiguation); or capitalization and spelling errors such as (Disambiguation), (DISAMBIGUATION), and (dsambiguation), which all have no more affinity to one disambiguated title over any other. The capitalization and spelling errors portion only applies if (x) is an error variation of "disambiguation" (e.g.  may or may not be appropriate for other reasons). Empty disambiguation, e.g. X , and double or more disambiguation, e.g. X (disambiguation) (disambiguation) (a malformed incomplete disambiguation in some cases), also lack affinity.
 * Note: User:DPL bot logs all links to DAB pages except ones precisely through a correctly-formed (disambiguation) qualifier as WP:INTDAB errors.


 * Unhelpful titles whose existence might encourage the few readers who stumble upon them to assume that there exist redirects of the same type for other targets as well (opening a "Pandora's Box" of user expectations)
 * e.g. titles that turn articles or article subtopics into questions, like Who was the first president of the United States? or What is the capital of France?; titles with informal abbreviations, such as Pres of United States or List of Seinfeld eps; titles with incorrect mixed use of non-Latin or otherwise inappropriate script, such as Варtism (where the Вар is in Cyrillic script) or Cl0ck (as a redirect to Clock); etc.
 * Titles that are commentary, often either defamatory or humorous. While insulting or humorous names do not per se make bad redirects, it should be considered whether there is a suitable page to match the intended target
 * e.g., someone searching Crazy Bernie is possibly not looking for Bernie Sanders, but for List of nicknames used by Donald Trump; if there is not a suitable target, the redirect is probably non-notable and/or "just commentary".

This is but a short list, and there are many more reasons for deletion.