Wikipedia:You can search, too

Avoid pestering other editors to retrieve information for you that you can get by yourself in seconds from any Internet search engine (or Wikipedia's internal advanced search). Such demands may be interpreted as annoying, unreasonable, and lazy. You are not more important than all the other volunteers on this project; they are not here to service you.

(However, it's perfectly understandable for an editor to sometimes need help finding information which is in another language, which requires specialist terminological knowledge to identify, or which needs complex search strings to isolate. It's also quite proper to expect that claims made in an article be sourceable, as a matter of WP:Verifiability policy.  Noticeboards also typically require diffs as evidence.)

Especially avoid a perception of "gaming the system" in consensus discussions by using repetitive or disingenuous demands ("sealioning") for sources, definitions, and other material already at your own fingertips. This is likely to be perceived as a petty form of disruptive editing. This includes using it for:
 * Filibustering dispute resolution
 * Bludgeoning RfCs and other discussions
 * Stalling with an "I just don't get it, I still need more information" routine
 * Pretending that a claim made in a discussion is dubious or unsourceable when it is self-evident, already explained, or even a small child can prove the statement with 30 seconds at a search engine.
 * Using lack of others' response to one's own lame dispute attempt as an excuse to make changes that simply reflect one's own familiarity or credulity.

A common sign this may be occurring is an archly, sarcastically, or snidely worded request for such instantly-findable information. An observable habit of making such pointless "show me" demands across many talk and process pages is a red flag. So is repeatedly demanding the same "help" when the editor has already been told how to find it. It does not require dramatic antics for an editor to be engaged in disrupting Wikipedia to make a point; simple obstructionism like any of the above also qualifies.

A related behavior is pretending that consensus discussions on talk pages are subject to the same core content policies as our article text. It isn't true, and it won't fool anyone.

Similar "show me!" wastes of other editors' time
Do not make petty demands that people do things like: or otherwise perform trivial tasks or exercise basic judgement that you can – and are expected to – routinely do for yourself.
 * show you exactly where in a Wikipedia page something is when it is easy to find;
 * re-state in the current section or page what you know they already posted earlier;
 * show you recent posts by an editor or changes at a page;
 * explain why a policy about X applies to the specific X you wish it didn't apply to;

Any experienced editor already knows how links work, how to search the text in a page, how to use page history to find diffs, and how to use the Contributions feature. Even a brand new editor must be competent enough to read a policy or guideline or process page and understand what it means (this is the same RTFM principle that applies throughout life).

If you are new to Wikipedia, click on the relevant blue-linked word in the above sentence for instructions.

Template
Let Me Google That for You ( LMGTFY.com ) doesn't work on WP because it's a URL redirector, but you can use the template to get the point across (and provide the search for them, so as not to be WP:POINTy in making the point).