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

 Message        <Context> conversion of the constant "<constant>" to
                <type> type will cause a change in sign.

 Description    Either an unsigned type was assigned a negative
                constant value, or a signed type was assigned a
                positive contant value which will be evalated as a
                negative number after the assignment.  Note that this
                message is not output for assignments to 1-bit
                bitfields.  The message bitconstsign is generated in
                that case.

 User Action    If this is what you intended, cast the constant to
                the desired type.  You might also want to change the
                constant to the correct signed or unsigned value in
                order to avoid the optional message intconcastsgn,
                which reports sign changes caused by casts.