/sys$common/syshlp/helplib.hlb MOUNT, Qualifiers, /UCS_SEQUENCE  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /UCS_SEQUENCE=escape_sequence

    Supplies the escape sequence to select the coded graphic
    character set, a requirement when mounting an ISO 9660 volume
    for one of the Supplementary Volume Descriptors (SVDs).

    The parameter, escape_sequence, is a character sequence defined
    by the vendor who mastered the CD-ROM and is unique to the
    vendor's character set conversion tables.

    Use the /UCS_SEQUENCE qualifier when mounting an ISO 9660 CD-ROM
    that contains non-ASCII character sets on OpenVMS.

    An ISO 9660 volume may contain an SVD that specifies a graphic
    character set. This graphic character, when selected at mount
    time, is used as default character set when displaying a volume's
    directories and file names.

    The /UCS_SEQUENCE qualifer defines the escape sequence to select
    the coded graphic character set.

    All ISO 9660 volumes contain a Primary Volume Descriptor (PVD)
    that uses ASCII (ISO 646-IRV) as the character set. Both ISO 9660
    and OpenVMS file naming conventions use the same subset of ASCII
    characters when displaying a volume's directories and file names.