diff -r 1696e2789d91 Doc/library/functions.rst
--- a/Doc/library/functions.rst	Wed Aug 24 02:15:25 2011 +0200
+++ b/Doc/library/functions.rst	Wed Aug 24 23:09:15 2011 -0400
@@ -940,6 +940,12 @@
    The *file* argument must be an object with a ``write(string)`` method; if it
    is not present or ``None``, :data:`sys.stdout` will be used.
 
+   The default encoding used for the various system streams(:data:`sys.stdout`, 
+   :data:`sys.stdin`, :data:`sys.stderr`) is set to the value of 
+   PYTHONIOENCODING if defined, if it isn't defined it is gotten from 
+   the system file descriptor via :func:`os.device_encoding`, if that fails 
+   we try and get the encoding using :func:`locale.getpreferredencoding`,
+   and if that fails the encoding defaults to ascii.
 
 .. function:: property(fget=None, fset=None, fdel=None, doc=None)