PEP 446: clarify the status of python 3.3 on Windows

Be more explicit

pep-0446.txt

@@ -318,29 +318,31 @@ child process.
 On Windows, the ``subprocess`` closes all handles and file descriptors
 in the child process by default. If at least one standard stream (stdin,
 stdout or stderr) is replaced (ex: redirected into a pipe), all
-inheritable handles are inherited in the child process.
+inheritable handles and file descriptors 0, 1 and 2 are inherited in the
+child process.
 
-All inheritable file descriptors are inherited by the child process
-using the functions of the ``os.execv*()`` and ``os.spawn*()`` families.
+Using the functions of the ``os.execv*()`` and ``os.spawn*()`` families,
+all inheritable handles and all inheritable file descriptors are
+inherited by the child process.
 
 On UNIX, the ``multiprocessing`` module uses ``os.fork()`` and so all
 file descriptors are inherited by child processes.
 
-On Windows, all inheritable handles are inherited by the child process
-using the ``multiprocessing`` module, all file descriptors except
-standard streams are closed.
+On Windows, all inheritable handles and file descriptors 0, 1 and 2 are
+inherited by the child process using the ``multiprocessing`` module, all
+file descriptors except standard streams are closed.
 
 Summary:
 
-===========================  =============  ==================  =============
-Module                       FD on UNIX     Handles on Windows  FD on Windows
-===========================  =============  ==================  =============
-subprocess, default          STD, pass_fds  none                STD
-subprocess, replace stdout   STD, pass_fds  all                 STD
-subprocess, close_fds=False  all            all                 STD
-multiprocessing              all            all                 STD
-os.execv(), os.spawn()       all            all                 all
-===========================  =============  ==================  =============
+===========================  ================  ==================  =============
+Module                       FD on UNIX         Handles on Windows  FD on Windows
+===========================  ================  ==================  =============
+subprocess, default          STD, pass_fds     none                STD
+subprocess, replace stdout   STD, pass_fds     all                 STD
+subprocess, close_fds=False  all               all                 STD
+multiprocessing              (not applicable)  all                 STD
+os.execv(), os.spawn()       all               all                 all
+===========================  ================  ==================  =============
 
 Legend:
 
@@ -351,6 +353,8 @@ Legend:
   inherited in the child process
 * "pass_fds": file descriptors of the *pass_fds* parameter of the
   subprocess are inherited
+* "(not applicable)": on UNIX, the multiprocessing uses ``fork()``,
+  so this case is not concerned by this PEP.
 
 
 Performances of Closing All File Descriptors