Why have Community Wiki posts?
One of the goals of the website is to be a continually evolving source of good information. Community Wiki posts help enhance the wiki aspect of the site.
For more information about the proper use of community wiki, see The Future of Community Wiki.
How do Community Wiki posts work?
Community Wiki posts work by partly transferring ownership of the post from the original author to the community. They make the post easier to edit and maintain by a wider group of users, but they do not contribute to any user's reputation.
Some of the key features are:
- A much lower reputation (100 instead of 2000) is needed to freely edit a community wiki post originally made by someone else. 1
- Voting on a community wiki post (up or down) does not affect any user's reputation.
- Accepting an answer marked as community wiki does not affect its original author's reputation, and does not give +2 to the question author.
- Bounties awarded to answer marked as community wiki still give reputation to the original author.
- The original author still gets badges based on community posts.
- The original author keeps the reputation gained (or lost) before their post entered community mode.
- The original author still receives notifications for substantial edits or comments on the post.
- The user listed in the author box need not be the original author. Rather, it is the user with the highest percentage of authorship in the final revision, determined by the number of lines inserted or deleted, with a bonus (factor of 2) for the original author.
How does a post become a Community Wiki post?
There are only three ways that a post becomes community wiki.
The answer's (not question's) author checks the community wiki checkbox when composing or editing the answer. Note that this checkbox isn't available to new users. The checkbox also is not available if the question being answered is already a community wiki. 2
If you post an answer to a community wiki question, your answer will also be community wiki.
A moderator has reason to believe that the question or answer serves better in community wiki mode - if you believe your post should be converted to a community wiki, you may flag it for moderator attention.
In the past, questions could be made community wiki by their authors or by certain automatic triggers but now the only means is by a moderator converting it to community wiki. When a moderator converts a question to community wiki, all existing answers will also be converted in addition to converting future answers.3
How can the Community Wiki status be removed from a post?
Community Wiki status can only be removed by a moderator.
If community wiki status is removed from a post, reputation is automatically recalculated as if the post was never a wiki.
Rollbacks cannot remove community wiki status.
The Community User4 might appear as the last editor of a post, even a non-wiki post. This happens either 1. when an edit by an anonymous user is approved, or 2. when it randomly pokes old unanswered questions so they get some attention. In the latter case, this will only be shown in certain overviews and on a notice on the question, and not an actual revision in the revision history.
If you are looking for an example community wiki post, see this question and this answer. They are all community wikis. You can easily identify community wikis by the text "community wiki" where the author's profile picture should be.
1 The original author of a community wiki post can always edit it, even if he or she has < 100 reputation. Other edits made by users with less than 100 reputation must be reviewed in the usual way before being applied.
2 Since October 2010, there is no community wiki checkbox when asking a question.
3 In the past, converting a question to community wiki would not automatically convert the answers, so you may see non-Community Wiki answers to older Community Wiki questions. Additionally, if a non-Community Wiki question is merged into a Community Wiki question, the imported answers will not be automatically converted. If you would like to edit them, you can flag for a moderator to add Community Wiki status to the answer. (Newer answers to these older questions will automatically be Community Wiki.)
4 See Who is the Community User?, or read the Community User’s profile.