There's also the UPU S1 standard for a common vocabulary for postal addresses. A couple of years ago I was working on implementing it for a large logistics cust

There's also the UPU S1 standard for a common vocabulary for postal addresses. A couple of years ago I was working on implementing it for a large logistics customer. Postal addresses are actually a field where XML can be put to good use. An international address would look like a piece of semistructured text with all formatting into multiple lines etc. preserved, with portions of text such as ZIP codes, names, etc. tagged with elements.