From Divinity Engine Wiki
- call TriggerRegisterForItems((TRIGGERGUID)_Trigger)
Ensures that whenever any item enters resp. leaves _Trigger, an ItemEnteredTrigger resp. ItemLeftTrigger event is thrown for this trigger/item combination, as well as an ItemTemplateEnteredTrigger resp. ItemTemplateLeftTrigger event.
- Unlike with character triggers, registering a trigger for items will not throw ItemEnteredTrigger/ItemTemplateEnteredTrigger events for all items already in that trigger.
- Items in a character's inventory do not trigger this event when the character enters/exits the trigger.