@item
This function is missing on some platforms:
OpenBSD 3.8, Minix 3.1.8, AIX 4.3.2, IRIX 6.5, OSF/1 5.1, Solaris 9, MSVC 9, Interix 3.5.
+@item
+This function fails on valid input strings on some platforms:
+AIX 5.1.
@end itemize
Portability problems not fixed by Gnulib: