Help:Revert
From Wod
Reverting a page is simply a fancy way of describing a way to return it to an earlier version. To revert a page, simply click its "History" tab and open the date and time of the version you want to revert to. Doing this will open an editing window so all you need to do is save this page.
The great thing about reversion is that it's easy. People who take sick joy in vandalizing a page have little time to celebrate.
The horrible thing about reversion is that it's easy. In edit wars, where two or more people constantly change an entry because they don't agree on what it should be, reversion is a common tactic. Such wars are wastes of time and frustrating beyond measure. If you find yourself in one, make your own version of the entry.