diff --git a/readme.md b/readme.md
index 6f7b860..46f0fd9 100644
--- a/readme.md
+++ b/readme.md
@@ -28,5 +28,5 @@ supports all the keys minetest does
 
 special keys:
 ```
-@_drop: called when a player drops an item
+@_drop: called when a player drops an item (note: only supported in register_on_press api method)
 ```
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