+@item
+This function does not support a @code{NULL} file name argument on some
+platforms:
+OpenBSD 4.9, AIX 7.1, HP-UX 11.23, IRIX 6.5, OSF/1 5.1, Solaris 10, mingw, MSVC 9.
+@item
+This function does not fail when the file name argument ends in a slash
+and (without the slash) names a nonexistent file or a file that is not a
+directory, on some platforms:
+HP-UX 11.00, Solaris 9, Irix 5.3.
+@item
+Applications should not assume that @code{fileno(f)} will be the same
+before and after a call to @code{freopen(name,mode,f)}. However, the
+module freopen-safer can at least protect @code{stdin}, @code{stdout},
+and @code{stderr}.