VMS Help MERGE, /COLLATING_SEQUENCE, Full Description  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    By default, Sort/Merge arranges records according to ASCII
    sequence. However, it can also arrange records according to
    EBCDIC and Multinational sequence.

    These three collating sequences can be modified to meet your
    particular needs through the use of a specification file. You can
    also define your own collating sequence by using a specification
    file if one of the three collating sequences does not suit your
    needs.