Fahrtanzeiger

Machine-translated from the German article

A Fahrtanzeiger (also called a Signalfahrtanzeiger or Signalnachahmer, abbreviated SFA) is a light signal located on or at platforms. When a train stops in a station, it indicates to the person in charge of train supervision (usually the train driver) whether the departure signal or intermediate signal for their train, or, when stopping at a halt, another nearby main signal, is showing a proceed aspect, since only in that case may they give the train its departure order. Fahrtanzeigers are not signal-technically safe and are not railway signals within the meaning of the Eisenbahn-Signalordnung, but merely orientation signs.