Thailand's vehicle registration plates are issued by the Department of Land Transport (DLT) of the Ministry of Transport. They must be displayed on all motorized road vehicles (with the exception of royal-, police- and military-owned vehicles), as required by the Motor Vehicle Act, B.E. 2522 (1979 CE) and the Land Transport Act, B.E. 2522. The plates vary in design, colors and dimensions according to the type of vehicle, but usually display a registration number (usually a two-character letter or numerical prefix and a four-digit number) and the vehicle's province of registration. Specifications are given in Ministry of Transport regulations. Current style started in 1975 for most vehicle types, but with small changes in 1997, and 1997 for motorcycles.