@section @code{towupper}
@findex towupper
-POSIX specification: @url{http://www.opengroup.org/susv3xsh/towupper.html}
+POSIX specification: @url{http://www.opengroup.org/onlinepubs/9699919799/functions/towupper.html}
Gnulib module: ---
@itemize
@item
This function is missing on some platforms:
-Solaris 2.5.1.
+IRIX 5.3, Solaris 2.5.1.
+@item
+On AIX and Windows platforms, @code{wchar_t} is a 16-bit type and therefore cannot
+accommodate all Unicode characters.
@end itemize