London boroughs, with the exception of the "square mile" of the City of London, the London boroughs all include some districts which would not be considered to be part of "central London" at least by some of the stricter definitions. London boroughs can be defined in terms of 'inner' or 'outer' London, but cannot be defined as central or otherwise. However, the London Plan in 2004 defined the Central London sub-region as comprising the boroughs of Kensington and Chelsea, Camden, Islington, Wandsworth, Lambeth, Southwark and the City of Westminster, omitting the City of London itself.