diff --git a/ROMFS/px4fmu_common/init.d/rcS b/ROMFS/px4fmu_common/init.d/rcS
index 5ec916cd0f..b6e3c9a4d4 100644
--- a/ROMFS/px4fmu_common/init.d/rcS
+++ b/ROMFS/px4fmu_common/init.d/rcS
@@ -592,6 +592,7 @@ then
 	else
 		if ver hwcmp PX4FMU_V4 PX4FMU_V4PRO MINDPX_V2
 		then
+			# This is TELEM4 on Pixhawk 3 Pro
 			frsky_telemetry start -d /dev/ttyS6
 		fi
 	fi