VMS Help CMS, DELETE, GROUP, Restrictions  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    o  You cannot delete a group that contains any elements or groups
       unless you specify the /REMOVE_CONTENTS qualifier.
    o  You cannot delete a group that belongs to another group.
    o  You cannot delete a group that has read-only access. (Use the
       MODIFY GROUP/NOREAD_ONLY command to change the access to the
       group.)