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

   o  Digital Test Manager does not insert the same group into another
      group more than once. If the first group is already a subgroup
      of the second group, Digital Test Manager informs you that the
      INSERT operation has already been done.

   o  Digital Test Manager does not create recursive group structures.
      If group B is a subgroup of group A, then group A cannot be a
      subgroup of group B.