It's the wiki page that logs your IP when you edit a page as a "guest". It does this for accountability issues. If you log in, they know your username and an e-mail to contact you at. This is something they would use (or bother with) only in cases where it has been reported that someone has maliciously edited a page. I would imagine they (the wiki people) could also use that and their databases transaction logs to remove that malicious edit.