added a note about the ignore_dangling_symlinks option
diff --git a/Doc/library/shutil.rst b/Doc/library/shutil.rst
index 4191e0e..d089dc4 100644
--- a/Doc/library/shutil.rst
+++ b/Doc/library/shutil.rst
@@ -103,7 +103,8 @@
exist, a exception will be added in the list of errors raised in
a :exc:`Error` exception at the end of the copy process.
You can set the optional *ignore_dangling_symlinks* flag to true if you
- want to silence this exception.
+ want to silence this exception. Notice that this option has no effect
+ on platforms that don't support :func:`os.symlink`.
If *ignore* is given, it must be a callable that will receive as its
arguments the directory being visited by :func:`copytree`, and a list of its