This signal is used to give the train driver the depature order , but also serves as a repeater : when it's lit the next signal shows an "approach" or "clear" aspect , when it's dark the next signal shows a "stop" aspect.Whereas in other countries the departure signal is only lit when the actual departure order is given , in the Netherlands the departure signal is also lit when no train is arriving and thus minimizes the actual function as a departure signal.