This function does not support the @samp{a} and @samp{A} directives on some
platforms:
glibc-2.3.6.
+@item
+This function does not support precisions larger than 512 or 1024 in integer,
+floating-point and pointer output on some platforms:
+AIX 7.1.
@end itemize
Portability problems not fixed by Gnulib:
@itemize
+@item
+On some platforms, this function does not set @code{errno} or the
+stream error indicator on attempts to write to a read-only stream:
+Cygwin 1.7.9.
@end itemize