#1582: document __reversed__, patch by Mark Russell.
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index 4f86fc7..693af64 100644
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -977,12 +977,16 @@
 
 .. function:: reversed(seq)
 
-   Return a reverse :term:`iterator`.  *seq* must be an object which supports
-   the sequence protocol (the :meth:`__len__` method and the :meth:`__getitem__`
-   method with integer arguments starting at ``0``).
+   Return a reverse :term:`iterator`.  *seq* must be an object which has
+   a :meth:`__reversed__` method or supports the sequence protocol (the
+   :meth:`__len__` method and the :meth:`__getitem__` method with integer
+   arguments starting at ``0``).
 
    .. versionadded:: 2.4
 
+   .. versionchanged:: 2.6
+      Added the possibility to write a custom :meth:`__reversed__` method.
+
 
 .. function:: round(x[, n])