Add renaming notices to 2.6 dbm module docs.
diff --git a/Doc/library/whichdb.rst b/Doc/library/whichdb.rst
index 5c69818..7048a0e 100644
--- a/Doc/library/whichdb.rst
+++ b/Doc/library/whichdb.rst
@@ -1,10 +1,14 @@
-
 :mod:`whichdb` --- Guess which DBM module created a database
 ============================================================
 
 .. module:: whichdb
    :synopsis: Guess which DBM-style module created a given database.
 
+.. note::
+   The :mod:`whichdb` module's only function has been put into the :mod:`dbm`
+   module in Python 3.0.  The :term:`2to3` tool will automatically adapt imports
+   when converting your sources to 3.0.
+
 
 The single function in this module attempts to guess which of the several simple
 database modules available--\ :mod:`dbm`, :mod:`gdbm`, or :mod:`dbhash`\