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

    Used in conjunction with the /NOSHARE qualifier to create
    a group volume. The group volume allows access by system
    (S),  owner (O), and group (G)  accessors. The protection is
    (S:RWCD,O:RWCD,G:RWCD,W).

    The owner user identification code (UIC) of the volume defaults
    to your group number and a member number of 0.