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

 Message        This nested include file appears to be unused.

 Description    The contents of this include file are not used by the
                rest of the compilation.

 User Action    For compilation efficiency, you can exclude this
                include file when compiling with the current set of
                compilation options.