This command only applies in multiuser mode.
aclgrp username [groupname]
Creates groups of users that share common access rights. The name of the group is the username of the group leader. Each member of the group inherits the permissions that are granted to the group leader. That means, if a user fails an access check, another check is made for the group leader. A user is removed from all groups if the special value “none” is used for groupname. If the second parameter is omitted all groups the user is in are listed.