The Next Volume service allows you to process the next tape
    volume in a multiple volume set. This service applies only to
    files on magnetic tape volumes.

                         RAB64 USERS (ALPHA ONLY)

       On Alpha systems, RAB64 can replace the RAB or RAB prefix
       wherever it is used with the Next Volume service on OpenVMS
       Alpha systems.

    Format

      SYS$NXTVOL  rab [,[err] [,suc]]