The VALUE OF ID clause specifies, replaces, or completes a file
  specification.

  Format -

   VALUE OF { ID      } IS { file-name }
            { FILE-ID }    { data-name }

1  –  file-name

  is a nonnumeric literal.  It contains the full or partial file
  specification.

2  –  data-name

  is the data-name of an alphanumeric Working-Storage data item.
  It contains the full or partial file specification.