GSS Office for National Statistics (ONS) have reconfigured their GSS coding structure (providing a unique system of referencing for administrative units) to a new 9 character alpha numeric format,replacing the current alpha numeric format (up to 6 characters).This change has now been implemented in this October 2010 release of Boundary-Line. However,the new GSS Coding and Naming policy for some statistical geographies will be implemented on 1 January 2011. From this date, where new codes have been allocated they should be used in all exchanges of statistics and published outputs that normally include codes. The following types of unit are coded where they have been made available by ONS: Counties, Districts, Wards/Electoral Divisions, London Boroughs, Unitary Authorities, GLA's, Parish/Communities, Euro Regions, Welsh Assembly Const and Electoral Regions, Scottish Parliamentary Const and Electoral Regions, Westminster Const. Description of http://data.ordnancesurvey.co.uk/ontology/admingeo/gssCode