VMS Help SHOW, LOGICAL, Qualifiers, /DESCENDANTS  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /DESCENDANTS
       /NODESCENDANTS (default)

    Controls whether the system displays names from the specified
    logical name table and any descendant tables. A descendant table
    is created by the CREATE/NAME_TABLE command, with the /PARENT_
    TABLE qualifier specifying its parent table. If you use the
    /DESCENDANTS qualifier, you must also use the /TABLE qualifier.