Community Wiki posts are not separate; rather, they are posts which the author has marked as
community wiki. These posts are designed to allow as many people to contribute as possible without allowing spammers in.
Community Wiki posts can be identified because they do not display an avatar; furthermore, you will see an
edit link even though they are not your on posts.
The option to make posts community wiki is a small checkbox in the lower right when answering questions—however, only check this box when sure, as you will not receive reputation.
FAQ for Community Wiki posts