The process by which users can vote to undelete and return it to the view of the public.
Voting to undelete posts is an option available to high-reputation users, allowing them to return content to the view of the public.
At 10,000 reputation, users gain access to moderator tools which allow them to cast undelete votes on questions which have been closed for at least two days and deleted.
As 20,000 reputation, a user becomes a trusted user allowing them to cast undelete votes on any question or answer which has been deleted.
Users cannot vote to undelete posts which were deleted by moderators. If a post is deleted by a moderator, it must also be undeleted by a moderator.
Once a certain threshold of undelete votes is reached, the post in question is automatically undeleted. Note that this does not reopen the question, if it was closed.