The central system administrator (or superuser) can create and remove user lnodes. This administrator may alter the limits, usages, and flags of any user, including its own, and also set administrative privileges for any lnode, including assigning administrative privileges selectively to users.
A sub-administrator can be granted these privileges by the setting of the flag.uselimadm flag. A sub-administrator can execute any limadm command as user root, and can be thought of as an assistant to the superuser.
A user granted hierarchical administrative privilege by the setting of the flag.admin flag is called a group administrator. A group administrator can modify the lnodes of users within the sub-tree of which they are the group header, and manage the group's resource allocation and scheduling policy. Group administrators cannot alter their own limits or flags, and cannot circumvent their own flags or limits by altering flags or usages within their group.