diff --git a/portnums.proto b/portnums.proto
index ed43f9c..b07d1c8 100644
--- a/portnums.proto
+++ b/portnums.proto
@@ -82,15 +82,19 @@ enum PortNum {
      * Connect to the RX/TX pins of a device with 38400 8N1. Packets received from the Meshtastic
      * network is forwarded to the RX pin while sending a packet to TX will go out to the Mesh
      * network. Maximum packet size of 240 bytes.
-     */
-    
-    /*
-     * Plugin is disabled by default can be turned on by setting SERIALPLUGIN_ENABLED = 1 in SerialPlugh.cpp
-     * 
+     *
      * Maintained by Jm Casler (MC Hamster) : jm@casler.org
      */
     SERIAL_APP = 64;
 
+    /*
+     * Provides a mechanism for external notifications. eg:
+     *     LED, Buzzer, Fog Horn or anything else
+     *
+     * Maintained by Jm Casler (MC Hamster) : jm@casler.org
+     */
+    EXTERNAL_NOTIFICATION_APP = 65;
+
     /*
      * Private applications should use portnums >= 256.
      * To simplify initial development and testing you can use "PRIVATE_APP"