diff --git a/libraries/AP_GPS/AP_GPS.cpp b/libraries/AP_GPS/AP_GPS.cpp
index 6ca80fccc82fe..0a1cbec4d3e51 100644
--- a/libraries/AP_GPS/AP_GPS.cpp
+++ b/libraries/AP_GPS/AP_GPS.cpp
@@ -2002,6 +2002,7 @@ bool AP_GPS::gps_yaw_deg(uint8_t instance, float &yaw_deg, float &accuracy_deg,
     // @Values: 0:None,1:AUTO,2:uBlox,5:NMEA,6:SiRF,7:HIL,8:SwiftNav,9:DroneCAN,10:SBF,11:GSOF,13:ERB,14:MAV,15:NOVA,16:HemisphereNMEA,17:uBlox-MovingBaseline-Base,18:uBlox-MovingBaseline-Rover,19:MSP,20:AllyStar,21:ExternalAHRS,22:DroneCAN-MovingBaseline-Base,23:DroneCAN-MovingBaseline-Rover,24:UnicoreNMEA,25:UnicoreMovingBaselineNMEA,26:SBF-DualAntenna
     // @RebootRequired: True
     // @User: Advanced
+    // @Legacy: only included here so GCSs running stable can get the description.  Omitted in the Wiki.
 
     // @Param: _TYPE2
     // @CopyFieldsFrom: GPS_TYPE