This removes user from the user list.
/ruser [levels] <nick | address> [type]
If you specify levels then these levels are removed from the current access levels of this user. If all levels a user user has have been removed, the user will be removed too. If you specify a type then the users address is looked up with a /userhost and any users in the users list matching this address are removed.
If you put an exclamation mark after the nick (e.g. /ruser foobar!), it removes all users with an address beginning with foobar!.
This would remove Dana from your user list.
ruser Dana 2
This would remove all users matching *!*@staff.quakenet.org as type 2 of Dana's address (Danaemail@example.com) is *!*@staff.quakenet.