The districts of England are a level of subnational division of England used for the purposes of local government. As the structure of local government in England is not uniform, there are currently four principal types of district-level subdivision. They are London boroughs, metropolitan districts, non-metropolitan districts, and unitary authorities. The City of London and the Isles of Scilly are also districts, but do not correspond to any of these categories. Some districts are styled as boroughs, cities, or royal boroughs; these are purely honorific titles, and do not alter the status of the district. All boroughs and cities, and a few districts, are led by a Mayor who in most cases is a ceremonial figure elected by the council, but after local government reform is occasionally a directly elected mayor who takes most of the policy decisions instead of the council.