C_and_STDCALL

 Specify how data is to be passed when you use routines written in C
 or assembler with FORTRAN or Fortran 95/90 routines.

 C and STDCALL are interpreted as synonyms.

 When applied to a subprogram, these properties define the
 subprogram as having a specific set of calling conventions.

 The difference between the calling conventions is this: If C or
 STDCALL is specified for a subprogram, arguments (except for
 arrays and characters) are passed by value.  Subprograms using
 standard Fortran 95/90 conventions pass arguments by reference.

 Character arguments are passed as follows:

  o  By default, hidden lengths are put at the end of the argument
     list.

  o  If C or STDCALL (only) is specified:

     On all systems, the first character of the string is passed
     (and padded with zeros out to INTEGER(4) length).

  o  If C or STDCALL is specified, and REFERENCE is specified for
     the argument:

     On all systems, the string is passed with no length.

  o  If C or STDCALL is specified, and REFERENCE is specified for
     the routine (but REFERENCE is not specified for the argument,
     if any):

     On all systems, the string is passed with the length.