Indicates the status of a file when it is opened.  It takes the
  following form:

  STATUS = sta

  sta  Is a character expression with one of the following
       values:

  'OLD'       Open an existing file.

  'NEW'       Create a new file; if the file already exists an
              error occurs.

  'SCRATCH'   Create a new file and delete it when the file is
              closed.

  'REPLACE'   Replace the file with another. If the file to be
              replaced exists, it is deleted and a new file is
              created with the same name.  If the file to be replaced
              does not exist, a new file is created and its status
              changes to 'OLD'.

  'UNKNOWN'   Open the file as OLD; if it does not exist, then
              open the file as NEW.

  The default is 'UNKNOWN'.  However, if you implicitly open a file
  using WRITE or you specify compiler option /NOF77 (or OPTIONS
  /NOF77), the default value is 'NEW'.  If you implicitly open a file
  using READ, the default is 'OLD'.

  Scratch files (STATUS='SCRATCH') are created on the user's default
  disk (SYS$DISK) and are not placed in a directory or given a name
  that is externally visible.  To indicate a different device, use
  the FILE specifier.

                                 NOTE

          The  STATUS  parameter  is  also  used   in   CLOSE
          statements  to  specify  the status of a file after
          the file is closed.  However, in  CLOSE  statements
          the  STATUS values are the same as those listed for
          the DISPOSE specifier (see OPEN DISPOSE).