MediaWiki:Revdelete-text

Deleted revisions and events will still appear in the page history and logs, but parts of their content will be inaccessible to the public.
Administrators (who are not staff) will still be able to view anything you hide, unless you suppress it by checking off Suppress data from administrators as well as others. Doing this will only make the deleted information accessible to other staff members, and it won't be displayed in any public logs.