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

       /SEPARATED[=MASTER, REVISION]

    Lists sequentially only the records from the specified file
    that contain differences. Use the MASTER keyword to list the
    differences in the first input file specified; use the REVISION
    keyword to list the differences in the second input file
    specified.

    By default, the DIFFERENCES command creates only a merged list of
    differences.