diff --git a/neutron/plugins/openvswitch/common/constants.py b/neutron/plugins/openvswitch/common/constants.py
index da45415cae..9cf6637dac 100644
--- a/neutron/plugins/openvswitch/common/constants.py
+++ b/neutron/plugins/openvswitch/common/constants.py
@@ -45,6 +45,9 @@ LEARN_FROM_TUN = 10
 UCAST_TO_TUN = 20
 ARP_RESPONDER = 21
 FLOOD_TO_TUN = 22
+
+# Tables for integration bridge
+# Table 0 is used for forwarding.
 CANARY_TABLE = 23
 
 # Map tunnel types to tables number