I found this post, because I had the same question. I think this is a good idea. Every community develops written and unwritten rules. Most rules are covered in the faq, some can be found here at meta, but some are only found by getting it as you go, or worse, by getting slapped. Some are buried even deeper. A faq entry on answering would really help.
For instance: I only just found out that with the [homework] tag one is supposed to "guide the student in solving the problem, rather than simply showing the complete answer". It's very easy to miss the popup description of the tag and offer a full fletched solution.
Other examples where rules may apply:
- Answering your own question, when, why.
- Giving credit to sources from which you 'derive' an answer (to put it friendly).
- How to show that you edited an answer. Some explicitly start a paragraph with 'Edit:' or use strikeout, but often you only see that the answer was edited and some comments clearly apply to a previous version.
- When to answer in a comment (and potentially leave a question 'unanswered')
On the other hand, there is no obligation to read the faq, so would it have any effect?