The first system, introduced in 1900, consisted of a letter code denoting the province the vehicle was registered in (the full list of codes appears below), followed by a sequence number of up to six digits (codice_1). The codes were normally made up of the first one or two letters of the province name or the name of the provincial capital (many provinces are named after their capitals), under the provisions of a 1926 regulation. In the earliest days, some provinces used three-letter codes, but these were abolished after 1926.