The I-O-CONTROL paragraph specifies the input-output techniques to be
  used for a file.

  Format -

  I-O-CONTROL.

 [[      {| DEFERRED-WRITE                     |}                    ]
 [[      {| EXTENSION extend-amt               |}                    ]
 [[      {| FILL-SIZE                          |}                    ]
 [[      {| LOCK-HOLDING                       |}                    ]
 [[APPLY {| MASS-INSERT                        |} ON {file-name} ... ] ...
 [[      {|[CONTIGUOUS         ]
 [[      {|[CONTIGUOUS-BEST-TRY]
                      PREALLOCATION preall-amt |}                    ]
 [[      {| PRINT-CONTROL                      |}                    ]
 [[      {| WINDOW window-ptrs                 |}                    ]

  [     [ RECORD     ]                                               ]
  [SAME [ SORT       ]AREA FOR {same-area-file} {same-area-file} ... ] ...
  [     [ SORT-MERGE ]                                               ]

  [                           { { [END OF] { REEL } }             } ]
  [                           { {          { UNIT } } OF file-name} ]
  [RERUN [ON file-name] EVERY { { integer RECORDS   }             } ] ...
  [                           { integer CLOCK-UNITS               } ]
  [                           { condition-name                    } ]

  [MULTIPLE FILE TAPE CONTAINS {file-name [POSITION integer] } ... ] ...].]

1  –  extend-amt

  is an integer from 0 through 65535.  It specifies the number of blocks
  in each extension of a disk file.

2  –  preall-amt

  is an integer from 0 through 4,294,967,295.  It specifies the number
  of blocks to initially allocate when the program creates a disk file.

3  –  window-ptrs

  is an integer from 0 through 127.  Its value can also be 255.  It
  specifies the number of retrieval pointers in the window that maps the
  disk file.

4  –  file-name

  names a file described in a Data Division file description entry.

5  –  same-area-file

  names a file described in a Data Division File Description entry to
  share storage areas with every other same-area-file.