A little known feature of meta sites is that they can have a sidebar with a few most frequently asked questions: for example, Programmers Meta does. For a description of how it works, see FAQ sidebar for per site metas.
I propose to enable this sidebar here. Hopefully, it will cut down on the number of questions that are asked only to be quickly closed as a duplicate. The list of FAQ questions includes several evergreen topics such as MathJax, contacting a user, accepting answers, non-English posts, etc.
While we are looking at the faq questions, I propose to add the following frequently occurring topics to the tag, so that they show up in the aforementioned sidebar.
"Reopen/undelete this question": Requests for Reopen & Undeletion Votes, etc. (volume 01/2015 - ) [current version] (maybe the "volume" thing can be dropped from this; I don't see a problem with just using this one from now on).
"I was serially downvoted, what to do?". The canonical reference is, apparently, Cereal downvotes
"My question doesn't get answers and it's been like 20 minutes, what to do?". The best reference I see is How to grab users' attention on an old question?
Asking a proof-verification question: Best way of asking "check my proof" questions