Two tiny clarifications.

pep-0008.txt

@@ -506,7 +506,8 @@ Programming Recommendations
       'is' or 'is not'.  Also, beware of writing "if x" when you
       really mean "if x is not None" -- e.g. when testing whether a
       variable or argument that defaults to None was set to some other
-      value.
+      value.  The other value might be a value that's false in a
+      Boolean context!
 
     - Class-based exceptions are always preferred over string-based
       exceptions.  Modules or packages should define their own
@@ -554,7 +555,10 @@ Programming Recommendations
       reindent.py) will trim them.
 
     - Don't compare boolean values to True or False using == (bool
-      types are new in Python 2.3).
+      types are new in Python 2.3):
+
+        No:  if greeting == True: print "Hello world"
+        Yes: if greeting: print "Hello world"
 
 
 References