The SHOW UNUSED command determines whether an element has owners
    or members. The element must have a directory name.

    If the element does not have owners or members, the name and
    type of the element is displayed. If the element has owners
    or members, CDO sends an informational notice. If you receive
    an informational notice, issue the SHOW USES and SHOW USED_BY
    commands to identify these owners or members.