diff --git a/docs/marlin.rst b/docs/marlin.rst
index d3c60fe..9cfbae6 100644
--- a/docs/marlin.rst
+++ b/docs/marlin.rst
@@ -5,7 +5,7 @@ Marlin Firmware for Ramps or compatible
 
 Notes
 -----
-We use stadard marlin firmware to implement M3 / M4 GCode command
+We use standard marlin firmware to implement M3 / M4 GCode command. We use the CNC configuration to control the electro-magnet with the spindle / pen / laser commands (M3 / M4).
 
 Board configuration
 -------------------