Document changes on mbcs encoding
diff --git a/Doc/whatsnew/3.2.rst b/Doc/whatsnew/3.2.rst
index bd38a7e..7d8b2e6 100644
--- a/Doc/whatsnew/3.2.rst
+++ b/Doc/whatsnew/3.2.rst
@@ -544,3 +544,10 @@
opaque C pointers in Python objects, the :ctype:`PyCapsule` API should be used
instead; the new type has a well-defined interface for passing typing safety
information and a less complicated signature for calling a destructor.
+
+* mbcs encoding doesn't ignore the error handler argument anymore. By default
+ (strict mode), it raises an UnicodeDecodeError on undecodable byte sequence
+ and UnicodeEncodeError on unencodable character. To get the mbcs encoding of
+ Python 3.1, use ``'ignore'`` error handler to decode and ``'replace'`` error
+ handler to encode. mbcs now supports ``'strict'`` and ``'ignore'`` error
+ handlers for decoding, and ``'strict'`` and ``'replace'`` for encoding.