/[NO]MACHINE_CODE

  Controls whether the listing file includes a symbolic
  representation of the OpenVMS Alpha object code generated by the
  compiler.  Generated code and data are represented in a form
  similar to a MACRO assembly code 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 MACRO
  assembler.

  If a listing file is not being generated, the /MACHINE_CODE
  qualifier is ignored.

  The default is /NOMACHINE_CODE.

  See the HP Fortran for OpenVMS User Manual for a description of
  the format of a machine code listing.