The SORT statement creates a sort file by executing input procedures or
  transferring records from an input file.  It sorts the records in the
  sort file using one or more keys that you specify.  Finally, it returns
  each record from the sort file, in sorted order, to output procedures
  or an output file.

  Format -

   SORT sortfile { ON { ASCENDING  } KEY { sortkey } ... } ...
                 {    { DESCENDING }                     }

      [ WITH DUPLICATES IN ORDER ]

      [ COLLATING SEQUENCE IS alpha ]

      { INPUT PROCEDURE IS first-proc [ { THRU    } end-proc ] }
      {                               [ { THROUGH }          ] }
      { USING { infile } ...                                   }

      { OUTPUT PROCEDURE IS first-proc [ { THRU    } end-proc ] }
      {                                [ { THROUGH }          ] }
      { GIVING { outfile } ...                                  }

1 - sortfile

  is a file-name described in a sort-merge file description (SD) entry in
  the Data Division.

2 - sortkey

  is the data-name of a data item in a record associated with sortfile.

3 - alpha

  is an alphabet-name defined in the SPECIAL-NAMES paragraph of the
  Environment Division.

4 - first-proc

  is the section-name or paragraph-name of the first (or only) section or
  paragraph of the INPUT or OUTPUT procedure range.

5 - infile

  is the file-name of the input file. It must be described in a file
  description (FD) entry in the Data Division.

6 - end-proc

  is the section-name or paragraph-name of the last section or paragraph
  of the INPUT or OUTPUT procedure range.

7 - outfile

  is the file-name of the output file. It must be described in a file
  description (FD) entry in the Data Division.