diff -r ab4432daf69f Doc/using/cmdline.rst
--- a/Doc/using/cmdline.rst	Mon Oct 22 21:50:27 2012 -0700
+++ b/Doc/using/cmdline.rst	Tue Oct 23 13:23:04 2012 +0200
@@ -358,7 +358,8 @@
 .. cmdoption:: -X
 
    Reserved for various implementation-specific options.  CPython currently
-   defines none of them, but allows to pass arbitrary values and retrieve
+   defines just one, you can use ``-X faulthander`` to enable 
+   :data:`faulthandler`. It also allows to pass arbitrary values and retrieve 
    them through the :data:`sys._xoptions` dictionary.
 
    .. versionchanged:: 3.2