diff --git a/README.md b/README.md
index 0e8287b..ab83721 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# yamaha-sound-program-by-source
+# musiccat-repairkit
 
 Instead of having to manually change the sound program when you're switching from e.g. TV to Spotify and vice verse, let the computer do it for you.
 
@@ -25,6 +25,48 @@ Currently the following mappings from source to sound program are hard coded
     spotify => music with clear_voice disabled
     airplay => music with clear_voice disabled
 
+## Use case : sync volume from a device to another one
+
+1. Subscribe to events at the source device. It's UDP : the code for this part comes from [axelo/yamaha-sound-program-by-source](https://github.com/axelo/yamaha-sound-program-by-source)).
+
+2. In the events received, identify those who define a volume update.
+	# 2. Récupérer le volume sur la chaîne (controlé par télécommand IR / bouton en facade)
+	GET http://192.168.1.31/YamahaExtendedControl/v1/main/getStatus
+	-> contient /volume = 32
+
+	# 3. Positionner le volume des enceintes à la même valeur
+	GET http://192.168.1.33/YamahaExtendedControl/v1/main/setVolume?volume=20
+
+
+## Docker build & run
+
+Build :
+
+  docker-compose build
+
+Run locally, then stop :
+
+  docker-compose up --detach
+  docker-compose down
+
+Deploy on a swarm :
+
+  docker stack deploy -c docker-compose.yml musiccast-repairkit
+
+
+## MQTT
+
+https://github.com/ppt000/musiccast2mqtt
+https://musiccast2mqtt.readthedocs.io/en/latest/
+
+	pip install --user musicast2mqtt
+	musiccast2mqtt
+
+Marche bien, mais c'est du Python 2.
+On voit bien les events de mise à jour du volume.
+Le projet contient de la doc sur le protocole MusicCast également !
+
+
 # References
 
 http://habitech.s3.amazonaws.com/PDFs/YAM/MusicCast/Yamaha%20MusicCast%20HTTP%20simplified%20API%20for%20ControlSystems.pdf
@@ -32,3 +74,8 @@ http://habitech.s3.amazonaws.com/PDFs/YAM/MusicCast/Yamaha%20MusicCast%20HTTP%20
 https://www.pdf-archive.com/2017/04/21/yxc-api-spec-advanced/yxc-api-spec-advanced.pdf
 
 https://github.com/samvdb/php-musiccast-api
+
+
+# TODO
+
+Rename index.js to server.js and remove the start script from package.json (server.js is the default for npm start)
diff --git a/doc/YXC_API_Spec_Advanced.pdf b/doc/YXC_API_Spec_Advanced.pdf
new file mode 100644
index 0000000..51341ad
Binary files /dev/null and b/doc/YXC_API_Spec_Advanced.pdf differ
diff --git a/doc/YXC_API_Spec_Basic.pdf b/doc/YXC_API_Spec_Basic.pdf
new file mode 100644
index 0000000..3a14ac7
Binary files /dev/null and b/doc/YXC_API_Spec_Basic.pdf differ