diff --git a/ArduCopter/Parameters.cpp b/ArduCopter/Parameters.cpp
index 4d6883d18b..f9494a0e6a 100644
--- a/ArduCopter/Parameters.cpp
+++ b/ArduCopter/Parameters.cpp
@@ -1137,6 +1137,9 @@ const AP_Param::GroupInfo ParametersG2::var_info[] = {
     // @User: Standard
     AP_SUBGROUPINFO(command_model_pilot, "PILOT_Y_", 56, ParametersG2, AC_CommandModel),
 
+    // ID 62 is reserved for the SHOW_... parameters from the Skybrush fork at
+    // https://github.com/skybrush-io/ardupilot
+
     AP_GROUPEND
 };
 
diff --git a/ArduCopter/mode.h b/ArduCopter/mode.h
index 7d5f6e9371..66f47644b1 100644
--- a/ArduCopter/mode.h
+++ b/ArduCopter/mode.h
@@ -39,6 +39,9 @@ public:
         AUTOROTATE =   26,  // Autonomous autorotation
         AUTO_RTL =     27,  // Auto RTL, this is not a true mode, AUTO will report as this mode if entered to perform a DO_LAND_START Landing sequence
         TURTLE =       28,  // Flip over after crash
+
+        // Mode number 127 reserved for the "drone show mode" in the Skybrush
+        // fork at https://github.com/skybrush-io/ardupilot
     };
 
     // constructor