VMS Help FORTRAN, /DEBUG  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  /[NO]DEBUG[=(option[,...])]     D=/DEBUG=(PARAM=USED,NOSYMBOLS,TRACEBACK)

  Controls whether the compiler makes local symbol table and
  traceback information available to the debugger and the run-time
  error traceback mechanism, and whether the debugger is given
  information about all PARAMETER constants defined in the program
  unit or only those that are actually used.

  By default, if you omit the /DEBUG qualifier, the compiler produces
  only an address correlation table (equivalent to
  /DEBUG=(PARAMETERS=USED,NOSYMBOLS,TRACEBACK)).  If you specify
  /DEBUG without any options, the default is
  /DEBUG=(PARAMETERS=USED,SYMBOLS,TRACEBACK).  /DEBUG=ALL is
  equivalent to /DEBUG=(PARAMETERS=ALL,SYMBOLS,TRACEBACK.)

  Compaq recommends that /NOOPTIMIZE also be used when debugging
  Fortran programs.  Optimizations performed by the compiler can
  cause several different kinds of unexpected behavior when using the
  OpenVMS Debugger.  See your performance guide for more information
  on this subject.

  The compiler will issue an informational message recommending
  /NOOPTIMIZE if /DEBUG is used without the /NOOPTIMIZE qualifier.
  To disable this message, specify /OPTIMIZE explicitly.

  For details on how to debug a Compaq Fortran 77 program with the
  OpenVMS Symbolic Debugger, see your user manual.

  /NODEBUG is equivalent to /DEBUG=NONE.

1 - PARAMETERS

  Controls how PARAMETER constant definitions are communicated to the
  debugger, subject to the setting of SYMBOLS.

  PARAMETERS=USED, the default, specifies that only those PARAMETER
  constants that are actually used in the program unit are made known
  to the debugger.

  PARAMETERS=ALL specifies that all PARAMETER constants are made
  known to the debugger.  If many PARAMETER constants are defined,
  this can greatly increase the size of the object module and
  executable image.

2 - SYMBOLS

  Controls whether the debugger receives local symbol definitions for
  user-defined variables, arrays, (including dimension information),
  structures, PARAMETER constants, and labels of executable
  statements.

  Unless /DEBUG=PARAMETERS=ALL is in effect, only those PARAMETER
  constants actually used in the program unit are made known to the
  debugger.

3 - TRACEBACK

  Controls the production of an address correlation table so that the
  debugger and the run-time error traceback mechanism can translate
  virtual addresses into source program routine names and
  compiler-generated line numbers.

4 - ALL

  Same interpretation as (PARAMETERS=ALL,SYMBOLS,TRACEBACK).

5 - NONE

  Same interpretation as (PARAMETERS=USED,NOSYMBOLS,NOTRACEBACK).