@section @code{putchar_unlocked}
@findex putchar_unlocked
-POSIX specification: @url{http://www.opengroup.org/onlinepubs/9699919799/functions/putchar_unlocked.html}
+POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/putchar_unlocked.html}
Gnulib module: ---
@itemize
@item
This function is missing on some platforms:
-mingw.
+Minix 3.1.8, mingw, MSVC 9.
+@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