Feature summary (what you would like to be able to do and where):

Special:GlobalVanishRequest and the associated mobile app interfaces should provide guidance and/or tools for requesting users to identify and tag their user pages for deletion prior to vanishing.

Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):

• As a user requesting vanishing, I want to ensure that all identifying information about my account, including my user page, is deleted or hidden according to community processes.
• As a local administrator, I must be sure that a request to delete a user page came from that user before deleting it.

Benefits (why should this be implemented?):

Multiple vanished users have been surprised that their user pages were not deleted and have requested assistance after vanishing. Because the vanishing process removes the user's email address and locks their account, there is no way for a local administrator to verify that the requests for deletion have come from the original account. While it is possible for a steward to unlock the account to allow the user to log back in, we also have no way to verify that the request came from the original account holder and do not intend to unlock vanished accounts outside of exceptional circumstances.

Ideally requesting users would be prompted with a wizard that would allow them to identify and tag all user pages (including subpages, if desired) with the relevant local deletion tag, but at the bare minimum there should be a warning and a link to Special:CentralAuth.