@itemize
@item
This function is missing on some platforms:
-HP-UX 11.00, OSF/1 4.0, Solaris 2.5.1, mingw, Interix 3.5, BeOS.
+HP-UX 11.00, OSF/1 4.0, Solaris 2.5.1, mingw, MSVC 9, Interix 3.5, BeOS.
+@item
+This function is declared in @code{<netdb.h>} instead of @code{<arpa/inet.h>}
+on some platforms:
+NonStop Kernel.
+@item
+This function is declared in @code{<ws2tcpip.h>}, with a POSIX incompatible
+declaration, on some platforms:
+MSVC 9 on Windows >= Vista.
@end itemize
Portability problems not fixed by Gnulib: