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

 Message        The declaration of a member that is an unnamed struct
                or union type is an extension and might not be
                portable.

 Description    Compaq C allows a member of a struct or union to be
                an unnamed struct or union type.  This is an
                extension of Compaq C that other compilers might not
                support.  In addition this behavior does not conform
                to the C standard.

 User Action    If portability is desired, provide a name for the
                struct/union member.