Index: Doc/reference/expressions.rst
===================================================================
--- Doc/reference/expressions.rst	(revision 62992)
+++ Doc/reference/expressions.rst	(working copy)
@@ -1115,7 +1115,7 @@
 
 The operators :keyword:`is` and :keyword:`is not` test for object identity: ``x
 is y`` is true if and only if *x* and *y* are the same object.  ``x is not y``
-yields the inverse truth value.
+yields the inverse truth value. [#]_
 
 
 .. _booleans:
@@ -1355,3 +1355,7 @@
    only, but this caused surprises because people expected to be able to test a
    dictionary for emptiness by comparing it to ``{}``.
 
+.. [#] Due to automatic garbage-collection, free lists, and the dynamic nature of 
+   descriptors, you may notice unusual behaviour in certain combinations of :keyword:`is` 
+   operator, like those involving identity comparisons between class and instancemethods, 
+   and free instances in the same expression. Check their docs for more info.