Short address is a NAC

A universal 'post code' that is said to pinpoint anywhere on (and off ) earth using fewer symbols than any other current system is being pushed by a Canadian software developer.

NAC Geographic Products says the Natural Area Code (NAC) makes data entry and storage more efficient. It is based on data used for GPS navigation systems, and can include altitude information measured from the earth's centre.

The system uses the digits zero to nine, and the English consonants in capitals to represent the 30 numbers zero to 29. The 360 degrees of longitude and 180 degrees of latitude (south being treated as negative) are split into 30 divisions, each represented by a single NAC symbol. These are also subdivided into 30 and sub-subdivided and so on - each subdivision represented by successive NAC symbols.

The NAC address for PCW is GZMS RKK1, the four-symbol words representing respectively the latitude and longitude; a third 'word', if present, would specify the altitude, say, of a balloon or plane above the building. The NAC for this is derived from the angle of a line drawn to the edge of the earth.

The system has already been correlated to street directories in 17 countries, including the UK, and applied to maps in several others. It can be used to get routing information from www.travelgis.com, where you can also find out the NAC for your own address - though be prepared for some persistent and annoying cascading ads.

Xinhang Shen, president of the company, says the system is unique in being able to encode concisely a point, a line, an area or a cube located anywhere from the centre of the earth to outer space.

One small point: the letters O and I can easily be confused with figures, but why not use the other three vowels in NAC codes? Explained Shen: 'It would be good for some people. But others might not like the words their address spelled out.'