Q:
A: It can be either deleted or oversighted by users with appropriate permissions. Deletion of a single edit is a bit awkward and time consuming but any administrator can do it. If the history contains numerous signatures with your ip as a talk page might, it may be impractical to delete it or even oversight it. Oversight is for removal of sensitive personal information. Only those with oversight permission can do it. Send requests for oversight to oversight-l@lists.wikimedia.org