diff --git a/docs/waypoint_data.md b/docs/waypoint_data.md
index acbb069c..9f5ec348 100644
--- a/docs/waypoint_data.md
+++ b/docs/waypoint_data.md
@@ -68,7 +68,9 @@ Time to wait (in ms) between each point.
 
 ### action
 
-ID of the action to be performed. See [waypoint\_scripts.id](waypoint_scripts).
+If positive, it's the ID of the action to be performed. See [waypoint\_scripts.id](waypoint_scripts).
+
+If negative, it sends DoAction(-action) to the creature (-123 \-\> DoAction(123)), which can be used in cpp and SAI scripts.
 
 ### action\_chance