diff --git a/pep-0511.txt b/pep-0511.txt
index b9e58af1b..1cffa46f0 100644
--- a/pep-0511.txt
+++ b/pep-0511.txt
@@ -125,6 +125,9 @@ preprocessor has various and different usages. Examples:
 `MacroPy <https://github.com/lihaoyi/macropy>`_ has a long list of
 examples and use cases.
 
+See also `PyXfuscator <https://bitbucket.org/namn/pyxfuscator>`_: Python
+obfuscator, deobfuscator, and user-assisted decompiler.
+
 
 Use Cases
 =========
@@ -378,6 +381,26 @@ Output::
     Ni! Ni! Ni!
 
 
+Other Python implementations
+============================
+
+The PEP 511 should be implemented be all Python implementation. The AST
+emited by the parser is not specified.
+
+By the way, even between minor version of CPython, there are changes on
+the AST API. There are differences, but only minor differences. It is
+quite easy to write an AST transformer which works on Python 2.7 and
+Python 3.5 for example.
+
+
+Discussion
+==========
+
+* `[Python-Dev] AST optimizer implemented in Python
+  <https://mail.python.org/pipermail/python-dev/2012-August/121286.html>`_
+  (August 2012)
+
+
 Prior Art
 =========
 
@@ -426,8 +449,13 @@ Modify the bytecode
   intricacies. See `byteplay documentation
   <http://wiki.python.org/moin/ByteplayDoc>`_.
 
-See also `BytecodeAssembler
-<http://pypi.python.org/pypi/BytecodeAssembler>`_.
+See also:
+
+* `BytecodeAssembler <http://pypi.python.org/pypi/BytecodeAssembler>`_
+* `Issue #2506 <https://bugs.python.org/issue2506>`_: Add mechanism to
+  disable optimizations
+* `[Python-ideas] Disable all peephole optimizations
+  <https://mail.python.org/pipermail/python-ideas/2014-May/027893.html>`_
 
 
 Copyright