diff --git a/Marlin/src/pins/pins_RADDS.h b/Marlin/src/pins/pins_RADDS.h
index 08bd1c9680..d17bc72b17 100644
--- a/Marlin/src/pins/pins_RADDS.h
+++ b/Marlin/src/pins/pins_RADDS.h
@@ -206,6 +206,9 @@
 
   #elif ENABLED(REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER)
 
+    // The REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER requires
+    // an adapter such as https://www.thingiverse.com/thing:1740725
+
     #define LCD_PINS_RS     42
     #define LCD_PINS_ENABLE 43
     #define LCD_PINS_D4     44