/sys$common/syshlp/helplib.hlb CC, Messages, INCLUDENOPEA  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Message        A non-default pointer size or member alignment is
                specified, and the header files in <directory> are
                not protected.  This might yield unpredictable
                results.  The protect_headers_setup script can help.
                See the protect_headers_setup(8) man page for
                details.

 Description    Using a non-default pointer size or member alignment
                can cause unpredictable results for system header
                files that are not protected and that rely on the
                default pointer size or alignment.

 User Action    Examine the man page referenced in the message for
                more information.