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

 Message        variant struct or union is a language extension.

 Description    Declaring a member to be a variant_struct or
                variant_union is a language extension of Compaq C.
                Other C compilers might not successfully compile a
                program that uses the extension.

 User Action    Consider using an anonymous struct or union (one
                without a tag or declarator) instead:  anonymous
                structs/unions are supported by Compaq C and some
                other vendors' C compilers.