Description

   The INSERT GROUP command inserts one or more groups into one
   or more other groups. Both groups must exist. When you use the
   INSERT GROUP command to insert group A into group B, the elements
   accessible through group B change as the contents of group A
   change. A group cannot be a member of itself; that is, it cannot
   be a subgroup of itself. For example, you cannot insert group A
   into group B if group A already contains group B.