This question is inspired by the Help spot deficiencies in our Help Center meta-question over at CodeReview.SE.
Just about every community, organization, business, government, etc., is governed by two sets of rules: the written rules & regulations, and the "community rules" (or the way things are done but not codified).
We are no exception. Our Help Center documents what's on-topic, what's off-topic, and the like, but is lacking in some of our more frequent, shall we say, admonitions? My favorite example is mattdm's excellent anti-answer-in-comments manifesto. When people answer in comments, you can expect a link back to that Meta question.
Another example is the set of "What's this effect?" –type questions.
But these are tripwire situations — the "rule book" didn't mention those scenarios, and posters usually find out about the violation only after they've broken the social rule.
Those are just a couple examples. I'm sure there are many more.
In the interest of possibly drafting better Help Center pages in the near future, can we identify where our Help Center pages are deficient or lacking?
This is intended to be a brainstorming type of question, rather than detailed rewording of Help Center pages. I'm sure that will follow after the brainstorming... =)