diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index 9796d735c..16c8ffc19 100755
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -8354,7 +8354,7 @@ void process_next_command() {
         break;
 
       #if ENABLED(ABORT_ON_ENDSTOP_HIT_FEATURE_ENABLED)
-        case 540:
+        case 540: // M540: Set abort on endstop hit for SD printing
           gcode_M540();
           break;
       #endif