Message        A UCN escape sequence was encountered.

 Description    Universal Character Name (UCN) escape sequences were
                added to C in the C99 standard, and are processed in
                this language mode.  C compilers and dialects that do
                not specifically process UCNs will treat them as
                unrecognized escape sequences, and may silently
                ignore the backslash.

 User Action    Be aware of this if you wish to port the program.