diff --git a/ArduCopter/mode.h b/ArduCopter/mode.h
index 68cc168574..009e74edd8 100644
--- a/ArduCopter/mode.h
+++ b/ArduCopter/mode.h
@@ -639,6 +639,7 @@ private:
     void loiter_to_alt_run();
     void nav_attitude_time_run();
 
+    // return the Location portion of a command.  If the command's lat and lon and/or alt are zero the default_loc's lat,lon and/or alt are returned instead
     Location loc_from_cmd(const AP_Mission::Mission_Command& cmd, const Location& default_loc) const;
 
     SubMode _mode = SubMode::TAKEOFF;   // controls which auto controller is run
diff --git a/ArduCopter/mode_auto.cpp b/ArduCopter/mode_auto.cpp
index 5780ce7f56..bc4bb21ac9 100644
--- a/ArduCopter/mode_auto.cpp
+++ b/ArduCopter/mode_auto.cpp
@@ -1513,6 +1513,7 @@ void ModeAuto::do_takeoff(const AP_Mission::Mission_Command& cmd)
     takeoff_start(cmd.content.location);
 }
 
+// return the Location portion of a command.  If the command's lat and lon and/or alt are zero the default_loc's lat,lon and/or alt are returned instead
 Location ModeAuto::loc_from_cmd(const AP_Mission::Mission_Command& cmd, const Location& default_loc) const
 {
     Location ret(cmd.content.location);