VMS Help Sys Parameters, MAXSYSGROUP  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    MAXSYSGROUP sets the highest value that a group number can have
    and still be classified as a system UIC group number. Note that
    the specification is not in octal unless preceded by the %O radix
    indicator. This parameter is normally left at 8 (10 octal).

    MAXSYSGROUP is a DYNAMIC parameter.