I've been looking at postal address standards. I used an ad-hoc one for my business RDF format experiment, but I felt sure that there should be some prior art

One common format is vCard and a proposal was made last year for representing vCard in RDF.

vCard divides an address into 7 sub-structures: Post Office Box, Extended Address, Street Address, Locality, Region, Postal Code and Country.

The cover pages has a section devoted to Markup Languages for Names and Addresses. These include the International Address Element Code which defines a vast number of address elements including 'Stairwell number' and 'Checkdigit for nine digit ZIP code', Address Data Interchange Specification [cover pages] which seems to define a even greater number of elements!

For people and businesses to self-describe, the element set has to be simple enough for average web-literate people to comprehend. For interesting applications to be built with this data it has to be rich enough to enable inter-linking. There has to be a balance between the two. Perhaps the use of ISO country codes isn't too arduous, and zip/post codes provide a large amount of information in a compact format. Requiring TGN to be used would be too hard, I feel.

I also found an RDF schema for contact information in the W3 semantic web area which takes a simplistic approach.

An interesting idea to explore would be an address uri-scheme in a similar vein to the telephone uri-scheme. If the Relative URIs could describe addresses in the same town or region. My address might look like:

address:/GB/Northamptonshire/Kettering/Rothwell/Kettering Road/43

and a relative reference to a friend's house in a neighbouring village might be

address:../../../Desborough/Rothwell Road/22

Of course, a simplistic scheme like this could never work in practice due to localised forms of country names and non-standard spellings (is it southend-on-sea or southend on sea). Also, a change in administrative regions would mean invalidating a whole swathe of URIs.

Some resoures:

• International Posting Union: Addressing Formats - links to PDF files describing the address format for each country with examples.
• ISO 3166 - standards for country name codes
• World Postal Codes and Other Useful links
• PostInfo - a portal for address management.