document UnicodeError attributes
diff --git a/Doc/library/exceptions.rst b/Doc/library/exceptions.rst
index 6c80df7..c12e874 100644
--- a/Doc/library/exceptions.rst
+++ b/Doc/library/exceptions.rst
@@ -387,6 +387,30 @@
Raised when a Unicode-related encoding or decoding error occurs. It is a
subclass of :exc:`ValueError`.
+ :exc:`UnicodeError` has attributes that describe the encoding or decoding
+ error. For example, ``err.object[err.start:err.end]`` gives the particular
+ invalid input that the codec failed on.
+
+ .. attribute:: encoding
+
+ The name of the encoding that raised the error.
+
+ .. attribute:: reason
+
+ A string describing the specific codec error.
+
+ .. attribute:: object
+
+ The object the codec was attempting to encode or decode.
+
+ .. attribute:: start
+
+ The first index of invalid data in :attr:`object`.
+
+ .. attribute:: end
+
+ The index after the last invalid data in :attr:`object`.
+
.. versionadded:: 2.0