For questions about the privileges trusted users gain, users with at least 20k reputation (4k on public betas).
Crack 20,000 reputation on a site and pop your beverage of choice, you're now a trusted user. Put up your feet and watch the truck back up and shower you with some more actions to enact on the good site itself.
Untold riches in site functions now avail themselves unto you, such as:
- Voting to delete answers such as with score of -1 or lower
- Voting to undelete answers except those deleted by a moderator
- Voting to delete questions immediately after they are closed (even if they are new)
- And editing tag wikis without needing approval
You need 4,000 reputation on a public beta or 2,000 on a private beta to get this privilege.