Indicates the name of the file to be connected to the unit.  It
  takes the following form:

  FILE = name

  name   Is a character or numeric expression.

  The "name" can be any pathname (or specification) allowed by the
  operating system.  (See the appropriate manual in the OpenVMS
  operating system documentation set.)

  Any trailing blanks in the name are ignored.

  If the following conditions occur:

   o  FILE is omitted

   o  The unit is not connected to a file

   o  STATUS='SCRATCH' is not specified

  then VSI Fortran generates a file name in the form FORnnn.DAT,
  where "nnn" is the logical unit number (with leading zeros, if
  necessary).

  If the file name is stored in a numeric scalar or array, the name
  must consist of ASCII characters terminated by an ASCII null
  character (zero byte).  However, if it is stored in a character
  scalar or array, it must not contain a zero byte.