What are “Community Wiki” posts?
What kind of permissions are required to mark another person's questions as community wikis? Is this only available to moderators?
From the FAQ question (which is the reference to follow, I only copy the current version here, it might not be actual in the coming months):
How does a post become a Community Wiki post?
There are several ways a question or answer can enter community wiki mode, and most of these ways will occur automatically based on the rules of the system.
Posts enter community wiki mode when:
- The body of the post has been edited six (6) times by at least four (4) different people.
- The post has been edited eight (8) times by the original owner.
- The post's author checks the community wiki checkbox when composing the question or answer. Note that this checkbox is only available to users with a reputation of 15 or more.
- The post is edited by its original author, who when doing so opts to check the community wiki.
- An answer posted to a Community Wiki question will also be Community Wiki. Note that when a question is made CW after answers have already been posted, the existing answers are not normally converted to CW automatically.
- The question generates more than 30 answers (15 on Super User). In this case, the question and all answers will enter community mode, as will any future answers.
- A moderator has reason to believe that the question serves better in community wiki mode.
* note that the rules outlined above are based on observations; the actual behavior of SO is subject to change without notice, and may well have done so since this was last updated...