If your list is moderated (announcement-only) so that only approved messages may be posted to the list, you might have list moderators (who are only in charge of approving messages to the list) who are different from the list administrators (who are in charge of the list settings and other technical aspects of list management).

http://lists.uua.org/mailman/admin/listname/?VARHELP=general/moderator ("Details for moderator") is the page that allows you to enter the email address(es) of your list moderators.

http://lists.uua.org/mailman/admin/listname/passwords ("Passwords") lets you set a moderator password that's different from the administrator password.

See "Moderator Requests" for more information about approving/discarding messages sent to the list.