From CUNY Academic Commons
Wikis are by their very nature open, public, and democratic. A wiki page grows as contributors collaborate and nurture its content. Users should not be scared off by this aspect of wikis, and should be aware that all versions of a wiki page are automatically saved, and it is quite easy to reverse unwanted changes.
Private Wikis on the Commons…
Still hesitant about the putting up your content on the public wiki? Need to collaborate on confidential content? The Commons also has BuddyPress Docs, which a wiki-like document handling interface with granular permissions settings. Click here for more information on BuddyPress Docs.