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

    o  You cannot insert an element into a group that has read-only
       access.
    o  You cannot insert an element into a group if the element
       already belongs to the group.
    o  You cannot insert an element into a group in another library
       (the element and group must be in the same library).