RER station panels show which stations are available on this RER line, in this direction. Station names lit with yellow squares indicate that the next train to arrive will stop at these stations.
This is a photo of an old style RER B stations served panel located at Luxembourg RER station.
At the bottom right hand corner is a square to specify whether the next train will be short or long. If the train is short, don’t wait for it at the extreme ends of the station platform, as the train will stop in the middle and you’ll have to rush back to the center of the platform to board the train.
Here’s a modern style RER B stations served panel at Antony station. This panel shows direction as “Aéroport Ch. de Gaulle 2 TGV” (which stops at Terminal 1 as well), wait time of 0 minutes, and the “mission” or itinerary name of the train: EFLA. Secret tip: any trains with mission names starting with the letter “E”, go to Airport Charles de Gaulle.