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

 Message        The specified linkage is undefined.  Pragma is
                ignored.

 Description    The linkage specified in a #pragma use_linkage
                directive has not been defined by an earlier #pragma
                linkage directive.  The compiler will ignore the
                entire pragma.

 User Action    Either define the linkage first or change the linkage
                name.