The national postal service, Correo Argentino, was established in 1854, privatized in 1997, and partly re-nationalized in 2003. There are no standard abbreviations for provinces' names; but the province name is optional and usually not needed if the postal code is correct. The format of the postal code was expanded in 1998 to include more specific information on location within cities; it now uses a letter that identifies the province, a four-digit number, and then three more letters (and slightly different numbers are used for different parts of a city, which was formerly done only in the case of Buenos Aires).