Ticket #20448: 20448.diff

docs/ref/models/instances.txt

@@ -434 +434 @@
 <Model.__str__>`) in a number of places. Most notably, to display an object in
 the Django admin site and as the value inserted into a template when it
 displays an object. Thus, you should always return a nice, human-readable
-representation of the model from the ``__unicode__()`` method.
+representation of the model from the ``__unicode__()`` method. Because this
+method may be called from Django internals outside of code you write, you
+should be aware of any unintended side effects, including queries resulting
+from fetching information on related models.
 
 For example::