Index: Doc/library/pickle.rst
===================================================================
--- Doc/library/pickle.rst	(revisión: 70360)
+++ Doc/library/pickle.rst	(copia de trabajo)
@@ -459,6 +459,16 @@
       value, the :meth:`__setstate__` method will not be called.
 
 
+.. note::
+
+   At unpickling time, some methods like :meth:`__getattr__`,
+   :meth:`__getattribute__`, :meth:`__setattr__` may be called upon the
+   instance. In case those methods rely on some internal invariant being true,
+   the type should implement either :meth:`__getinitargs__` or
+   :meth:`__getnewargs__` to establish such invariant; otherwise, neither
+   :meth:`__new__` nor :meth:`__init__` will be called.
+
+
 Pickling and unpickling extension types
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^