Fixed #22063 -- Added reference to NoReverseMatch from the reverse() documentation

docs/ref/urlresolvers.txt

@@ -23,6 +23,9 @@ keyword arguments to use in the URL matching. For example::
     def myview(request):
         return HttpResponseRedirect(reverse('arch-summary', args=[1945]))
 
+If no match can be made, ``reverse()`` raises a
+:class:`~django.core.urlresolvers.NoReverseMatch` exception.
+
 The ``reverse()`` function can reverse a large variety of regular expression
 patterns for URLs, but not every possible one. The main restriction at the
 moment is that the pattern cannot contain alternative choices using the