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

 Message        <Context> old-style parameter "<name>", with type
                that requires default argument promotion, cannot be
                used with va_start.

 Description    It is invalid for the parameter specified in va_start
                to be one that requires default argument promotion.

 User Action    The recommended fix is to recode the function
                definition to use a prototype-format definition.  It
                is also possible to change the parameter declaration
                to use one of the default types, for example double.