Address Point is a mapping/GIS data product supplied by Great Britain's national mapping agency, Ordnance Survey. It is based on the UK’s postal mail organisation, the Royal Mail, list of postal addresses, Postcode Address File (PAF). The most significant difference between Royal Mail list and Address Point is that Address Point includes the geographic coordinates of each postal address. This enables users to map the individual addresses. The Ordnance Survey website describes Address Point as: OSAPRs are always 18 characters long and must start with the letters AP.