Oversight, also known as suppression is a form of enhanced page deletion on a wiki running the MediaWiki software. Unlike normal page deletion, which can usually be performed and reversed by wiki administrators, oversight expunges and removed the deleted material/data from being viewed by anyone, including administrators and bureaucrats. The only users who can view or restore data that was deleted with Oversight are users with the
suppressrevision userright, which is by default granted to the "oversight" user group (the group is known as "suppress" on wiki's running MediaWiki version 1.25 and earlier).
Oversight is generally only used to remove serious vandalism or copyright infringement, personally identifiable information, or other grossly inappropriate content that should not be viewed by administrators. Oversight can be applied when deleting an entire page, or when deleting revisions/log entries using RevisionDeletion (in MediaWiki version 1.16+). Before version 1.16 which is when RevisionDeletion was introduced, the Oversight extension was used to accomplish the same purpose, however this was inefficient because the data could only be restored by a sysadmin via the database if there was a mistake. Now, even oversighted revisions and pages can be restored by a user with oversight access.