Clarify dunders.

pep-0008.txt

@@ -413,12 +413,31 @@ Imports
   public and internal interfaces still apply.
 
 
-Dunder Variables
-----------------
+Module level dunder names
+-------------------------
 
-All relevant dunder variables (e.g. ``__all__``, ``__author__``,
-``__version__``, etc) should be placed after the module docstring and
-before any imports, separated by a blank line above and below.
+Module level "dunders" (i.e. names with two leading and two trailing
+underscores) such as ``__all__``, ``__author__``, ``__version__``,
+etc. should be placed after the module docstring but before any import
+statements *except* ``from __future__`` imports.  Python mandates that
+future-imports must appear in the module before any other code except
+docstrings.
+
+For example::
+
+    """This is the example module.
+
+    This module does stuff.
+    """
+
+    from __future__ import barry_as_FLUFL
+
+    __all__ = ['a', 'b', 'c']
+    __version__ = '0.1'
+    __author__ = 'Cardinal Biggles'
+
+    import os
+    import sys
 
 
 String Quotes