/sys$common/syshlp/helplib.hlb FORTRAN, /MACHINE_CODE  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  /[NO]MACHINE_CODE               D=/NOMACHINE_CODE

  Controls whether the listing file includes a symbolic
  representation of the object code generated by the compiler.
  Generated code and data are represented in a form similar to a VAX
  MACRO assembly listing.  The code produced by the /MACHINE_CODE
  qualifier is for informational purposes only.  It is not intended
  to be assembled and is not supported by the VAX MACRO assembler.

  The default is /NOMACHINE_CODE, which omits machine language code
  in the listing.  The /MACHINE_CODE qualifier is ignored if /LIST is
  not specified, either explicitly or by default.

  For more information on the format of a machine code listing, see
  your user manual.