Four kinds of authority stand behind the six controls the law already requires. The more kinds that point at the same control, the better corroborated the duty — so a control's bar is built out of its kinds. One colour means one kind is carrying the call; four means courts, statute and the profession agree.
Bar length measures proof, not urgency. The rows are ordered by how little warning the record gave, so a control with twenty sources can sit below one with twelve. Hover any kind or any control to trace where the authority sits.