diff --git a/scripts/lte-firmware-alert.rsc b/scripts/lte-firmware-alert.rsc
index 7b9b64a..c21dc7a 100644
--- a/scripts/lte-firmware-alert.rsc
+++ b/scripts/lte-firmware-alert.rsc
@@ -1,3 +1,5 @@
+# Ref: https://wiki.mikrotik.com/wiki/Manual:Interface/LTE#Modem_firmware_upgrade
+
 :local lteFirmwareInfo [/interface lte firmware-upgrade lte1 as-value];
 
 :local lteInstalledVer ($lteFirmwareInfo->"installed");