Conform to Barry's new PEP referencing guidelines.

pep-0252.txt

@@ -403,7 +403,7 @@ Implementation
     here, see the file Lib/test/test_descr.py.
 
     Note: the code in this branch goes beyond this PEP; it is also
-    on the way to implementing pep-0253 (Subtyping Built-in Types).
+    on the way to implementing PEP 253 (Subtyping Built-in Types).
 
 References
 

pep-0253.txt

@@ -60,9 +60,9 @@ Introduction
     - a class statement can contain a slots declaration, specifying
       the specific names of the instance variables supported
 
-    This PEP builds on pep-0252, which adds standard introspection to
+    This PEP builds on PEP 252, which adds standard introspection to
     types; e.g., when the type object defines the tp_hash slot, the
-    type object has a __hash__ method.  pep-0252 also adds a
+    type object has a __hash__ method.  PEP 252 also adds a
     dictionary to type objects which contains all methods.  At the
     Python level, this dictionary is read-only for built-in types; at
     the C level, it is accessible directly (but it should not be
@@ -78,10 +78,10 @@ Introduction
     release.)
 
     In current Python, a distinction is made between types and
-    classes.  This PEP together with pep-0254 will remove that
+    classes.  This PEP together with PEP 254 will remove that
     distinction.  However, for backwards compatibility there will
     probably remain a bit of a distinction for years to come, and
-    without pep-0254, the distinction is still large: types ultimately
+    without PEP 254, the distinction is still large: types ultimately
     have a built-in type as a base class, while classes ultimately
     derive from a user-defined class.  Therefore, in the rest of this
     PEP, I will use the word type whenever I can -- including base
@@ -499,7 +499,7 @@ Subtyping in Python
     Assume B is a type object.  Since type objects are objects, and
     every object has a type, B has a type.  B's type is accessible via
     type(B) or B.__class__ (the latter notation is new for types; it
-    is introduced in pep-0252).  Let's say B's type is M (for
+    is introduced in PEP 252).  Let's say B's type is M (for
     Metatype).  The class statement will create a new type, C.  Since
     C will be a type object just like B, we view the creation of C as
     an instantiation of the metatype, M.  The information that needs
@@ -599,7 +599,7 @@ Implementation
     here, see the file Lib/test/test_descr.py and the extension module
     Modules/spam.c.
 
-    Note: the code in this branch is for pep-0252, pep-0253, and
+    Note: the code in this branch is for PEP 252, PEP 253, and
     pep-254.