What type of trailers used in agriculture and forestry do not have to have their own registration number?

According to German traffic rules, trailers used in agriculture and forestry that have a "25" speed limit sign attached to the rear do not need their own registration number. This sign indicates that the trailer is limited to a maximum speed of 25 km/h, which is a specific regulation for such vehicles. Trailers without this speed restriction must be registered and have their own number plate. The important point is the speed limitation sign; simply transporting agricultural goods or moving faster than 25 km/h requires registration. This helps control safety on public roads by distinguishing slower, specialized trailers from faster, regular ones.