Tape_Expiration=date-time

    Specifies the expiration date of the backup (.rbf) file. Note
    that when RMU Backup reads a tape, it looks at the expiration
    date in the file header of the first file on the tape and assumes
    the date it finds in that file header is the expiration date for
    the entire tape. Therefore, if you are backing up an .rbf file to
    tape, specifying the Tape_Expiration qualifier only has meaning
    if the .rbf is the first file on the tape. You can guarantee that
    the .rbf file will be the first file on the tape by specifying
    the Rewind qualifier and overwriting any existing files on the
    tape.

    When the first file on the tape contains an expiration date
    in the file header, you cannot overwrite the tape before the
    expiration date unless you have the OpenVMS SYSPRV or BYPASS
    privilege.

    Similarly, when you attempt to restore a .rbf file from tape,
    you cannot perform the restore operation after the expiration
    date recorded in the first file on the tape unless you have the
    OpenVMS SYSPRV or BYPASS privilege

    By default, no expiration date is written to the .rbf file
    header. In this case, if the .rbf file is the first file on the
    tape, the tape can be overwritten immediately. If the .rbf file
    is not the first file on the tape, the ability to overwrite the
    tape is determined by the expiration date in the file header of
    the first file on the tape.

    You cannot explicitly set a tape expiration date for an entire
    volume. The volume expiration date is always determined by the
    expiration date of the first file on the tape.

    The Tape_Expiration qualifier cannot be used with a backup file
    written to disk.

    See the Oracle Rdb Guide to Database Maintenance for information
    on tape label processing.