diff -r 3ab32f7add6e Doc/whatsnew/3.6.rst
--- a/Doc/whatsnew/3.6.rst	Fri Aug 19 18:59:15 2016 +0200
+++ b/Doc/whatsnew/3.6.rst	Fri Aug 19 15:50:31 2016 -0700
@@ -66,6 +66,10 @@
 
 * PEP 498: :ref:`Formatted string literals <whatsnew-fstrings>`
 
+Standard library improvements:
+
+* PEP 519: :ref:`Adding a file system path protocol <pep-519>`
+
 Windows improvements:
 
 * The ``py.exe`` launcher, when used interactively, no longer prefers
@@ -92,6 +96,52 @@
 New Features
 ============
 
+.. _pep-519:
+
+PEP 519: Adding a file system path protocol
+===========================================
+
+File system paths have historically been represented as :class:`str` or
+:class:`bytes` objects. This has led to people writing code which
+operates on file system paths to assume that a path is only one of
+those two types (an :class:`int` representing a file descriptor does
+not count as that is not a file path). Unfortunately that prevents
+alternative object representations of file system paths like
+:mod:`pathlib` from working with pre-existing code, including Python's
+standard library.
+
+To fix this situation so that any object can represent a path if it
+chooses to, a new interface represented by :class:`os.PathLike` has
+been defined. By implementing the :meth:`~os.PathLike.__fspath__`
+method, an object signals that it represents a path and can provide a
+low-level representation of a file system path as a :class:`str` or
+:class:`bytes` object. This means an object is considered
+:term:`path-like <path-like object>` if it implements
+:class:`os.PathLike` or is a :class:`str` or :class:`bytes` object
+which represents a file system path. Code can use :func:`os.fspath`,
+:func:`os.fsdecode`, or :func:`os.fsencode` to get explicitly get a
+:class:`str` and/or :class:`bytes` representation of a path-like
+object.
+
+The built-in :func:`open` function has been updated to accept
+:class:`os.PathLike` objects as has all relevant functions in the
+:mod:`os` and :mod:`os.path` modules. The :class:`os.DirEntry` class
+and relevant classes in :mod:`pathlib` have also been updated to
+implement :class:`os.PathLike`. The hope is that by updating the
+fundamental functions for operating on file system paths will lead
+to third-party code to implicitly supporting all
+:term:`path-like objects <path-like object>` without any code changes
+or at least very minimal ones (e.g. calling :func:`os.fspath` at the
+beginning of code before operating on a path-like object).
+
+(Implemented by Brett Cannon, Ethan Furman, Dusty Phillips, and Jelle Zijlstra.)
+
+.. seealso::
+
+    :pep:`519` - Adding a file system path protocol
+       PEP written by Brett Cannon and Koos Zevenhoven.
+
+
 .. _whatsnew-fstrings:
 
 PEP 498: Formatted string literals