The Rewind service sets the context of a record stream to the
    first record in the file. RMS alters the context of the next
    record to indicate the first record as being the next record.
                         RAB64 USERS (ALPHA ONLY)
       On Alpha systems, RAB64 can replace the RAB or RAB prefix
       wherever it is used with the Rewind service on OpenVMS Alpha
       systems.
    Format
      SYS$REWIND  rab [,[err] [,suc]]
Additional Information:
explode
extract