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

 Message        The anonymous struct or union member "<member name>"
                duplicates the name of a member in the enclosing
                struct or union.

 Description    As members of an anonymous structure or union are
                promoted to membership of the enclosing struct/union
                type, the names of each element of the anonymous
                struct/union must not match an element name in the
                enclosing struct/union.  This message can also be
                output when the variant_struct or variant_union
                syntax is used instead of the anonymous struct/union.

 User Action    Choose a new name for either the offending anonymous
                struct/union member or the matching member of the
                enclosing type.