Add Vedran's rejected proposal to PEP 526.

pep-0526.txt

@@ -567,6 +567,26 @@ Rejected/Postponed Proposals
   instead a TypeError will be raised if an attempt is made to update
   ``__annotations__`` when it is anything other than a dict.
 
+- **Treating bare annotations the same as global or nonlocal:**
+  The rejected proposal would prefer that the presence of an
+  annotation without assignment in a function body should not involve
+  *any* evaluation.  In contrast, the PEP implies that if the target
+  is more complex than a single name, its "left-hand part" should be
+  evaluated at the point where it occurs in the function body, just to
+  enforce that it is defined.  For example, in this example::
+
+    def foo(self):
+        slef.name: str
+
+  the name ``slef`` should be evaluated, just so that if it is not
+  defined (as is likely in this example :-), the error will be caught
+  at runtime.  This is more in line with what happens when there *is*
+  an initial value, and thus is expected to lead to fewer surprises.
+  (Also note that if the target was ``self.name`` (this time correctly
+  spelled :-), an optimizing compiler has no obligation to evaluate
+  ``self`` as long as it can prove that it will definitely be
+  defined.)
+
 
 Backwards Compatibility
 =======================