Issue #13777: Add PF_SYSTEM sockets on OS X.
Patch by Michael Goderbauer.
diff --git a/Doc/library/socket.rst b/Doc/library/socket.rst
index cb2ab23..6b7728f 100644
--- a/Doc/library/socket.rst
+++ b/Doc/library/socket.rst
@@ -99,6 +99,14 @@
``'can0'``. The network interface name ``''`` can be used to receive packets
from all network interfaces of this family.
+- A string or a tuple ``(id, unit)`` is used for the :const:`SYSPROTO_CONTROL`
+ protocol of the :const:`PF_SYSTEM` family. The string is the name of a
+ kernel control using a dynamically-assigned ID. The tuple can be used if ID
+ and unit number of the kernel control are known or if a registered ID is
+ used.
+
+ .. versionadded:: 3.3
+
- Certain other address families (:const:`AF_BLUETOOTH`, :const:`AF_PACKET`)
support specific representations.