Subject: [Ecrit] Civic address boundaries

From: "Thomson, Martin" <[email-masked]>
Date: Mon, 12 Jul 2010 14:39:51 +0800

I brought this document to last IETF, but didn't get air time at the meeting due to overcrowding:

  <http://tools.ietf.org/html/draft-thomson-ecrit-civic-boundary-00>

This attempts to rigorously define what a service boundaries for a civic address looks like and its properties.

The description in RFC 5222 is enough to scrape by, but when you have multilingual addresses, or you try to implement the rough-loc draft, then you encounter problems.  

For instance, does this boundary address:

	country: DE; A1 (lang="de"): Bayern; A1 (lang=“en”): Bavaria; 
	A3 (lang=“de”): München; A3 (lang=“en”): Munich; RD: Marienplatz

...contain this address?

	(lang=“en”) country: DE; A1: Bavaria; München; 
	A3: Munich; RD: Marienplatz; LMK: Rathaus; PC: 80331

There's a simple algorithm that can be used to test whether one civic address is "within" another.  There's also some discussion on the shortcomings of such simple tests, and some address- and border-combining algorithms.

--Martin