Hallvord wrote a few words about the BeforeScript event, adding something that caught my interest:
The event handler function receives an object with information about the event. The function can check various properties of this object to get information about the event. The element property tells you what element the event is happening to, and the event property is the event object that will be passed to the page’s script.
Hallvord’s quote provided me with a hint: The element refered to, acts mostly like any other DOM node. This means that you can check which properties are attached to the @