diff --git a/mesh.proto b/mesh.proto
index 76d4e3f..68f95ab 100644
--- a/mesh.proto
+++ b/mesh.proto
@@ -504,6 +504,11 @@ message Routing {
      */
     NO_RESPONSE = 8;
 
+    /*
+     * Cannot send currently because duty cycle regulations will be violated.
+     */
+    DUTY_CYCLE_LIMIT = 9; 
+
     /*
      * The application layer service on the remote node received your request, but considered your request somehow invalid
      */