Mercedes Benz S 212 (New E-Class T-Model) roof sign connection Taxi

When ordering my S 212, there is in the package “Special Model The Taxi” the extension feature “Dachzeichenanschluss für Taxi”. I would be interested in what exactly lies behind this designation? My existing cab canopy sign does not seem to be directly attached to this “Dachzeichenschluss für Taxi”, but first has to get me a corresponding holder for the cab canopy sign. Maybe one of you already has an S 212 and can w I would also like to draw on the experiences of the W 212 owners, because you also have this feature. Greeting Mica