diff -r a5c8bf5d1d5b Doc/reference/datamodel.rst
--- a/Doc/reference/datamodel.rst	Wed Apr 18 18:59:56 2012 +0200
+++ b/Doc/reference/datamodel.rst	Wed Apr 18 11:02:08 2012 -0700
@@ -1260,22 +1260,20 @@
    by default; with them, all objects compare unequal (except with themselves)
    and ``x.__hash__()`` returns ``id(x)``.
 
-   Classes which inherit a :meth:`__hash__` method from a parent class but
-   change the meaning of :meth:`__eq__` such that the hash value returned is no
-   longer appropriate (e.g. by switching to a value-based concept of equality
-   instead of the default identity based equality) can explicitly flag
-   themselves as being unhashable by setting ``__hash__ = None`` in the class
-   definition. Doing so means that not only will instances of the class raise an
-   appropriate :exc:`TypeError` when a program attempts to retrieve their hash
-   value, but they will also be correctly identified as unhashable when checking
+   Classes which change the meaning of :meth:`__eq__` (thus losing automatic
+   delegation to the parent class' :meth:``__hash__``) can explicitly flag
+   themselves as being unhashable by setting :meth:``__hash__ = None`` in the
+   class definition (which is otherwise done implicity). Having
+   :meth:``__hash__`` set to :const:``None``, either explicitly or implicitly,
+   means that not only will instances of the class raise an appropriate
+   :exc:`TypeError` when a program attempts to retrieve their hash value, but
+   they will also be correctly identified as unhashable when checking
    ``isinstance(obj, collections.Hashable)`` (unlike classes which define their
    own :meth:`__hash__` to explicitly raise :exc:`TypeError`).
 
    If a class that overrides :meth:`__eq__` needs to retain the implementation
    of :meth:`__hash__` from a parent class, the interpreter must be told this
-   explicitly by setting ``__hash__ = <ParentClass>.__hash__``. Otherwise the
-   inheritance of :meth:`__hash__` will be blocked, just as if :attr:`__hash__`
-   had been explicitly set to :const:`None`.
+   explicitly by setting ``__hash__ = <ParentClass>.__hash__``.
 
 
    .. note::