Create, edit, and remove admin and host logins.
Checking access…
Give someone their own admin.html login. A host only ever sees boards they create; an admin sees every board.
Hosts run their own separate boards. Click View Boards to switch the board admin page over to just their boards.
Other people with full admin access, same as you.
Every custom URL currently claimed, including any not attached to a visible host account below — delete one to free it up for reuse.