VMS Help CC, Messages, EXPANDEDDEFINED  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Message        Macro expansion includes the token "defined", which
                will be treated as an operator.  This might not be
                portable.

 Description    A macro expanded during the processing of a
                preprocessor #if directive included the token
                "defined".  The Compaq C/C++ compiler will treat this
                as the defined preprocessing operator.  Other
                compilers might treat this differently.

 User Action    Rewrite the macro not to use the "defined" operator.