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

 Message        "#<directive>" directive within a macro argument list
                is not portable.

 Description    Compaq C/C++ will allow certain directives to appear
                within the argument list of a macro invocation.  This
                might not be portable.

 User Action    If possible, rewrite the macro invocation.