diff --git a/doc/lua_api.md b/doc/lua_api.md
index 7b2a8945e..7f4d69021 100644
--- a/doc/lua_api.md
+++ b/doc/lua_api.md
@@ -7456,7 +7456,8 @@ Misc.
     * This function can be overridden by mods to change the leave message.
 * `core.hash_node_position(pos)`: returns a 48-bit integer
     * `pos`: table {x=number, y=number, z=number},
-    * Gives a unique hash number for a node position (16+16+16=48bit)
+    * Gives a unique numeric encoding for a node position (16+16+16=48bit)
+    * Despite the name, this is not a hash function (so it doesn't mix or produce collisions).
 * `core.get_position_from_hash(hash)`: returns a position
     * Inverse transform of `core.hash_node_position`
 * `core.get_item_group(name, group)`: returns a rating