List Flag: sub-approve

Indicates to listmanager that all new subscription requests require approval
before the subscriber is allowed to participate in the list's discussions.
If set, a subscriber is added to the list with the "pending" member flag
enabled.  This flag may not be set or cleared by the "mflags" command.

Upon receiving an attempt to subscribe, listmanager notifies the list owner(s)
that a subscription attempt was received, and adds the pending user.  The
list owner(s) then use either "approve" or "reject" to approve or reject
the request.

See also: approve reject