The NCS$RESTORE_CS routine, used in conjunction with the
    NCS$SAVE_CS routine, permits the application program to keep a
    local copy of the collating sequence. The NCS$SAVE_CS routine
    obtains the length and location of the collating sequence and
    returns it to the application program. The application program
    subsequently provides this information to the NCS$RESTORE_CS
    routine, which uses it to access the collating sequence.

    This routine also does some integrity checking on the collating
    sequence as it is being processed.