This is more of a question of community expectations or general recommendations than official rules, since I know that technically anyone can post an answer to a question.
It seems that most questions posted here are in the form of ordinary users asking for clarification, bug fixes, or features from the administrators and moderators.
Since these questions expect some kind of "official" response, it seems like it would be unwise for an ordinary user to post an answer to them.
Even with more discussion-oriented questions, it seems that the only people posting responses are those with enough time and experience on Stack Overflow to rather authoritatively know what "the community's" policy or opinion is.
So what exactly qualifies one to post an answer on a Meta Stack Overflow question?
Is there a guideline for how many years of experience or reputation points you should have on Stack Overflow before answering questions here?