Merge pull request #1554 from alex/reasons-enum
made the internal _Reasons an enum, since we already depend on enum34
diff --git a/docs/random-numbers.rst b/docs/random-numbers.rst
index 68a72cf..8b119a3 100644
--- a/docs/random-numbers.rst
+++ b/docs/random-numbers.rst
@@ -9,13 +9,16 @@
major security issues depending on the algorithms in use.
Therefore, it is our recommendation to `always use your operating system's
-provided random number generator`_, which is available as ``os.urandom()``. For
-example, if you need 16 bytes of random data for an initialization vector, you
-can obtain them with:
+provided random number generator`_, which is available as :func:`os.urandom`.
+For example, if you need 16 bytes of random data for an initialization vector,
+you can obtain them with:
.. doctest::
>>> import os
>>> iv = os.urandom(16)
+This will use ``/dev/urandom`` on UNIX platforms, and ``CryptGenRandom`` on
+Windows.
+
.. _`always use your operating system's provided random number generator`: http://sockpuppet.org/blog/2014/02/25/safely-generate-random-numbers/