Mention that the order-preserving aspect of the new dict
implementation is an implementation detail (and why that is so).
diff --git a/Doc/whatsnew/3.6.rst b/Doc/whatsnew/3.6.rst
index 34ebadd..a150d9d 100644
--- a/Doc/whatsnew/3.6.rst
+++ b/Doc/whatsnew/3.6.rst
@@ -416,7 +416,14 @@
* :func:`dict` now uses a "compact" representation `pioneered by PyPy
<https://morepypy.blogspot.com/2015/01/faster-more-memory-efficient-and-more.html>`_.
:pep:`468` (Preserving the order of ``**kwargs`` in a function.) is
- implemented by this. (Contributed by INADA Naoki in :issue:`27350`. Idea
+ implemented by this. The order-preserving aspect of this new
+ implementation is considered an implementation detail and should
+ not be relied upon (this may change in the future, but it is desired
+ to have this new dict implementation in the language for a few
+ releases before changing the language spec to mandate
+ order-preserving semantics for all current and future Python
+ implementations).
+ (Contributed by INADA Naoki in :issue:`27350`. Idea
`originally suggested by Raymond Hettinger
<https://mail.python.org/pipermail/python-dev/2012-December/123028.html>`_.)