Index: MsgDefs.h
===================================================================
diff -u -rfc1093b5c522659c74e7873b4fd6dd1df3b8e1b5 -r9ebc7a5eb4d5ca6fa80dbdff43692a2b95278c9f
--- MsgDefs.h	(.../MsgDefs.h)	(revision fc1093b5c522659c74e7873b4fd6dd1df3b8e1b5)
+++ MsgDefs.h	(.../MsgDefs.h)	(revision 9ebc7a5eb4d5ca6fa80dbdff43692a2b95278c9f)
@@ -8,8 +8,8 @@
 *
 * @file    MsgDefs.h
 *
-* @author  (last)      Michael Garthwaite
-* @date    (last)      15-Apr-2026
+* @author  (last)      Sameer Kalliadan Poyil
+* @date    (last)      16-Apr-2026
 *
 * @author  (original)  Sean Nash
 * @date    (original)  01-Aug-2024
@@ -300,7 +300,7 @@
     MSG_ID_DD_TEMPERATURE_SENSOR_MEASURED_TEMPERATURE_OVERRIDE_REQUEST = 0xA019,        ///< DD temperature sensor measured temperature override request
     MSG_ID_DD_TEMPERATURE_SENSOR_READ_COUNTER_OVERRIDE_REQUEST = 0xA01A,                ///< DD temperature sensor read counter override request
     MSG_ID_DD_TEMPERATURE_SENSOR_FILTERED_TEMP_OVERRIDE_REQUEST = 0xA01B,               ///< DD temperature sensor filtered temperature override request.
-    MSG_ID_DD_AVAILABLE_3 = 0xA01C,                                                     ///< DD Msg ID not used - available for use.
+    MSG_ID_DD_SET_OPERATION_SUB_MODE_OVERRIDE_REQUEST = 0xA01C,                         ///< DD set new operation sub mode override request
     MSG_ID_DD_DIALYSATE_PUMPS_PUBLISH_INTERVAL_OVERRIDE_REQUEST = 0xA01D,               ///< DD dialysate pumps data publish interval override request
     MSG_ID_DD_DIALYSATE_PUMPS_TARGET_SPEED_OVERRIDE_REQUEST = 0xA01E,                   ///< DD dialysate pumps target speed override request
     MSG_ID_DD_DIALYSATE_PUMPS_MEASURED_SPEED_OVERRIDE_REQUEST = 0xA01F,                 ///< DD dialysate pumps measured speed override request