A commercial vehicle trailer includes an electronically controlled braking system having an electronic control unit that has a parameter memory having one or more memory areas that can store vehicle-specific data. The electronic control unit controls the electronically controlled braking system based on the vehicle-specific data, and has an interface to an external computer. To permit reliable correlation of the vehicle-specific data to the commercial vehicle trailer, information is displayed on the trailer itself that characterizes the vehicle-specific data and that can be read into the computer via a reader unit. Based on such information, the appropriate vehicle-specific data is transferred to the electronic control unit.