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

 Message        In this declaration, "<name>" appears to be used as
                if it named a type, but there is no declared type of
                that name visible.

 Description    The compiler has encountered what appears to be a
                typedef declaration that provides a new name for an
                existing type, but the identifier used to specify the
                existing type is not the name of a type that is
                visible.

 User Action    Declare the identifier for the first type, or correct
                its spelling.