add an entry for object.__dir__
diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index 5b220d0..3d531c7 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -1314,6 +1314,11 @@
    should only be implemented if ``del obj.name`` is meaningful for the object.
 
 
+.. method:: object.__dir__(self)
+
+   Called when :func:`dir` is called on the object.  A list must be returned.
+
+
 .. _descriptors:
 
 Implementing Descriptors