VMS Help SORT, Output File Qualifiers, /INDEXED_SEQUENTIAL  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Defines the output file organization as indexed sequential. The
    output file must exist and must be empty. Used with the /OVERLAY
    qualifier.

    Format

      output-file-spec/INDEXED_SEQUENTIAL

1 - Full Description

    If the organization of the output file is to be different
    from that of the input files, then you must specify the
    new organization. Use the /INDEXED_SEQUENTIAL qualifier to
    define indexed-sequential organization for the output file.
    Additionally, the output file must exist and must be empty, and
    you must use the /OVERLAY qualifier.

2 - Example

  $ CREATE/FDL=NEW.FDL AVERAGE.DAT
  $ SORT/KEY=(POS:1,SIZ:80) DATA.DAT,STATS.DAT -
  _$ AVERAGE.DAT/INDEXED_SEQUENTIAL/OVERLAY

      The CREATE/FDL command creates the empty file AVERAGE.DAT. The
      SORT command specifies that the output file have an indexed-
      sequential organization and be written to the empty file
      AVERAGE.DAT.