diff --git a/force_bdss/factory_registry_plugin.py b/force_bdss/factory_registry_plugin.py
index d16342fb9a2d4c5c58be24740d1e361e2821a3ce..f11bbc3a5320f0f531899ef672ea85ef565dd247 100644
--- a/force_bdss/factory_registry_plugin.py
+++ b/force_bdss/factory_registry_plugin.py
@@ -43,6 +43,8 @@ class FactoryRegistryPlugin(Plugin):
         List(IKPICalculatorFactory),
         id=ExtensionPointID.KPI_CALCULATOR_FACTORIES)
 
+    #: Notification listeners are pluggable entities that will listen
+    #: to MCO events and act accordingly.
     notification_listener_factories = ExtensionPoint(
         List(INotificationListenerFactory),
         id=ExtensionPointID.NOTIFICATION_LISTENER_FACTORIES