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

 Message        <Context> "<expression>" of type "<type>", is being
                converted to "<target type>".

 Description    In certain modes, the compiler will allow assignments
                or comparisons between pointer and integer types.
                This is an extension to standard C.  Other C
                compilers might not successfully compile a program
                that uses this extension.

 User Action    Use a cast operator to convert one operand to the
                other.