Add versionchanged notes for PEP 380
diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst
index 7da54a2..9746162 100644
--- a/Doc/reference/expressions.rst
+++ b/Doc/reference/expressions.rst
@@ -355,7 +355,7 @@
 garbage collected), the generator-iterator's :meth:`close` method will be
 called, allowing any pending :keyword:`finally` clauses to execute.
 
-When ``yield from expression`` is used, it treats the supplied expression as
+When ``yield from <expr>`` is used, it treats the supplied expression as
 a subiterator. All values produced by that subiterator are passed directly
 to the caller of the current generator's methods. Any values passed in with
 :meth:`send` and any exceptions passed in with :meth:`throw` are passed to
@@ -369,6 +369,9 @@
 :exc:`StopIteration`, or automatically when the sub-iterator is a generator
 (by returning a value from the sub-generator).
 
+   .. versionchanged:: 3.3
+      Added ``yield from <expr>`` to delegate control flow to a subiterator
+
 The parentheses can be omitted when the :keyword:`yield` expression is the
 sole expression on the right hand side of an assignment statement.
 
diff --git a/Doc/reference/simple_stmts.rst b/Doc/reference/simple_stmts.rst
index d98b829..3bd0894 100644
--- a/Doc/reference/simple_stmts.rst
+++ b/Doc/reference/simple_stmts.rst
@@ -470,10 +470,13 @@
 garbage collected), the generator-iterator's :meth:`close` method will be
 called, allowing any pending :keyword:`finally` clauses to execute.
 
-When ``yield from expression`` is used, it treats the supplied expression as
+When ``yield from <expr>`` is used, it treats the supplied expression as
 a subiterator, producing values from it until the underlying iterator is
 exhausted.
 
+   .. versionchanged:: 3.3
+      Added ``yield from <expr>`` to delegate control flow to a subiterator
+
 For full details of :keyword:`yield` semantics, refer to the :ref:`yieldexpr`
 section.