NG: Flag for a non-geographic sector that contains only PO Box or Large User addresses. Data comes from Royal Mail. Updated lists appear to be released in July and January each year as part of the PAF Statistics.
Units: The total number of units (individual postcodes) listed in Code-Point Open
Geo. Units: An estimate of the number of geographic units, computed as follows: The number of postal units which either exist in OSM or have fewer than 5 or more other units with the same coordinates in Code-Point Open. This is designed to exclude PO Box units that are located at Royal Mail Delivery Offices.
Mapped: The number of unique valid units appearing as an addr:postcode value in OSM.
%: OSM progress towards mapping at least one example of each unit, measured against the number of geographic units.
