German vehicle registration plates ( or, more colloquially, ) are alphanumeric plates in a standardized format, issued officially by the district authorities to motorized vehicles of German residents. The legal requirements for these licence plates are laid down in a federal law titled (Ordinance on the admission of vehicles for road traffic), or in the shortened version which replaced part of an older law named in 2011. The law distinguishes between meaning a specific combination of letters and digits, and which are the physical licence plates. In everyday language, these terms are often replaced indifferently by and rarely is the difference emphasized by restricted use of either or . All motorized vehicles participating in road traffic on public space, whether moving or stationary, have to bear the plates allotted to them, displayed at the appropriate spaces at the front and rear. Additionally, the official seals on the plates show their validity which can also be proven by the documentation coming with them. Motorcycles and trailers carry only the rear plate. The system of number plates used on cars, buses, trucks, trailers and motorcycles is described below. Its most significant feature is the first part, an area code of one, two or three letters which used to tell the district of registration. It has developed into a widespread habit in Germany, even a children's game when travelling, to guess “where that vehicle is from”. A different system applies to smaller vehicles such as mopeds, cf. insurance plates. Format German number plates are rectangular, with standard dimensions for cars, trucks, buses and their trailers. Plates bearing few characters may have reduced length but must retain the size and shape of the characters. Plates in two lines for the said types of vehicles measure . Motorcycles also have plates in two lines but with specific dimensions: Plates for "large motorcycles" (engine displacement over 125 cc or power output exceeding ) issued until 2011 combine a size of with characters of the same size as used for car plates, while those issued since 2011 have characters of reduced size and measure either or . Plates for "light motorcycles" (Leichtkrafträder up to 125 cc and ) combine a size of with characters of reduced size. This smallest size of plates is also used for agricultural tractors with a maximum speed of and their trailers and may also be issued as an exception for certain import