Takes no part in autoscale: it covers bars, it is not one.
Never hit, so the click that picks a bar reaches the chart.
Moving or clearing the cut repaints at once: a host sets it on a click, not only on a pointer move.
Layer order vs series: 'bottom' (behind), 'normal' (over), 'top' (overlay).
Takes no part in autoscale: it covers bars, it is not one.