VMS Help CC, Messages, MIXLINKAGE1  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Message        <Context> "<name>" is declared with both internal and
                external linkage.  The previous declaration is at
                <location>.

 Description    This informational is output when a function
                previously declared to have extern storage class is
                redeclared to have internal storage class and the
                mode of the compiler is common (K & R) mode.

 User Action    Change one of the declarations so that the linkages
                match.