How do I 'Revert to a previous edit' ?

[TMA]

There have been a couple of times now when I have noticed a page has been spammed with junk (and invisible) links. I notice when HexMonkey and Arn find something similar and they fix it, it shows up in the history/recent changes as '(Reverted edit of 123.123.123.123, changed back to last version by HexMonkey)' - Is there a button I'm missing that allows me to do the same or is it a moderator only function?

At present I'm just manually deleting the unwanted content and leaving a quick note (e.g "deleted spam").

 

[HexMonkey]

Yeah, it's a feature only available to sysops. A "rollback" link appears on diff pages, which reverts the page to the last revision made by someone other than the user being reverted, and adds the reversion comment.

See here for more information.