Board Thread:Support Requests - Getting Technical/@comment-26601886-20151029015323/@comment-1757994-20151029032036

The deleterevision privilege provides that capability. Wikia staff have it. On some larger wikis, the admins have it.

Typically deleterevision is used only when leaving something visible, even in the history, would be a violation of TOU, like if someone got doxed, if someone under 13 doxed themselves, or if someone spammed links to a porn site.

It might be worth noting that nothing is ever really deleted. "Deleting" a page or a revision of a page just makes it unviewable to people who don't have the ability to see "deleted" revisions.