From the Deletions Guide:
-ARC refers to pages which have been archived instead of deleted outright. Archived pages are appended with -ARC. There are a few reasons for a page to be archived rather than deleted. Most often, it’s because an SCP is old and referenced in Tales, and its wholesale deletion would muddle works which reference it. There are also things that Staff simply want to keep around, albeit off the main list. The process for archiving a page is identical to the process for deletions, with suggestions for -ARC typically occurring after initiation of the deletion vote, save the page is renamed rather than culled.
Regular users may not add to this page, nor do you get a call in archiving your own article in most cases. For more information on these articles, please contact a staff member.