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

 Message        <Context> Compaq C recognizes the standard keyword
                "signed".  This differs from the VAX C behavior.

 Description    VAX C does not recognize the "signed" keyword.
                Compaq C will allow this, even in vaxc mode.

 User Action    Be aware of this difference if you plan to compile
                the source with VAX C.