From 08b2676a8f148574f73ef93f3425d7040eba2e51 Mon Sep 17 00:00:00 2001
From: Peter Barker <pbarker@barker.dropbear.id.au>
Date: Wed, 3 Jul 2019 16:15:54 +1000
Subject: [PATCH] AP_Notify: add comments explaining tonealarm tone format

---
 libraries/AP_Notify/ToneAlarm.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libraries/AP_Notify/ToneAlarm.cpp b/libraries/AP_Notify/ToneAlarm.cpp
index 2c0aae6626..54e81ba072 100644
--- a/libraries/AP_Notify/ToneAlarm.cpp
+++ b/libraries/AP_Notify/ToneAlarm.cpp
@@ -28,6 +28,9 @@
 
 extern const AP_HAL::HAL& hal;
 
+// Tunes follow the syntax of the Microsoft GWBasic/QBasic PLAY
+//   statement, with some exceptions and extensions.
+// See http://firmware.ardupilot.org/Tools/ToneTester/
 const AP_ToneAlarm::Tone AP_ToneAlarm::_tones[] {
 #define AP_NOTIFY_TONE_QUIET_NEG_FEEDBACK 0
     { "MFT200L4<<<B#A#2", false },