Add note about changes to the `round` function between 2.x and 3.x.
diff --git a/Doc/whatsnew/3.0.rst b/Doc/whatsnew/3.0.rst
index c748993..afec5fc 100644
--- a/Doc/whatsnew/3.0.rst
+++ b/Doc/whatsnew/3.0.rst
@@ -798,6 +798,15 @@
* A new built-in function :func:`next` was added to call the
:meth:`__next__` method on an object.
+* The :func:`round` function rounding strategy and return type have
+ changed. Exact halfway cases are now rounded to the nearest even
+ result instead of away from zero. (For example, ``round(2.5)`` now
+ returns ``2`` rather than ``3``.) :func:`round(x[, n])` now
+ delegates to ``x.__round__([n])`` instead of always returning a
+ float. It generally returns an integer when called with a single
+ argument and a value of the same type as ``x`` when called with two
+ arguments.
+
* Moved :func:`intern` to :func:`sys.intern`.
* Removed: :func:`apply`. Instead of ``apply(f, args)`` use