France is mainly divided into 18 administrative regions: 13 regions in metropolitan France (including the territorial collectivity of Corsica), and five located overseas. The regions are further subdivided into 101 departments, which are numbered mainly alphabetically. This number is used in postal codes and was formerly used on vehicle number plates. Among the 101 departments of France, five (French Guiana, Guadeloupe, Martinique, Mayotte, and Réunion) are in overseas regions (ROMs) that are also simultaneously overseas departments (DOMs), enjoy exactly the same status as metropolitan departments and are an integral part of the European Union. The 101 departments are subdivided into 335
Administrative county 1 October 1973. Section 131 of the Local Government Act (Northern Ireland) 1972 stated that ""every county and every county borough shall cease to be an administrative area for local government purposes"". The areas of the former administrative counties (and county boroughs) remain in use for Lieutenancy purposes, being defined as the areas used ""for local government purposes immediately before 1 October 1973, subject to any subsequent definition of their boundaries..."". In the Republic of Ireland the legislation that created them remained in force until the Local Government Act 2001 was passed, which renamed them 'counties'. The administrative counties that