diff --git a/nixos/machines/robi/webhook-ring.nix b/nixos/machines/robi/webhook-ring.nix
index 40ded34..8cdd421 100644
--- a/nixos/machines/robi/webhook-ring.nix
+++ b/nixos/machines/robi/webhook-ring.nix
@@ -1,4 +1,9 @@
 { config, pkgs, ... }:
+# To create a sign at the door
+# "Sorry Doorbell is broken, please scan this QR Code
+#
+# create QR Code with:
+# qrencode -o ./test.png http://ring.ingolf-wagner.de
 {
 
   sops.secrets.ringPushover = {