Mention that crc32 and adler32 are available in a different module (zlib).
Some people look for them in hashlib.
diff --git a/Doc/library/hashlib.rst b/Doc/library/hashlib.rst
index 8bba718..bfb007f 100644
--- a/Doc/library/hashlib.rst
+++ b/Doc/library/hashlib.rst
@@ -21,6 +21,10 @@
digest are interchangeable. Older algorithms were called message digests. The
modern term is secure hash.
+.. note::
+ If you want the adler32 or crc32 hash functions they are available in
+ the :mod:`zlib` module.
+
.. warning::
Some algorithms have known hash collision weaknesses, see the FAQ at the end.