Non-US addressing — comparative postcode systems, global gazetteers, locale-specific formats.
View All TagsMost sequence labelers throw away the parts of an address they don't understand, and the output format is built to hide it. We made ours hand every dropped character back, then aggregated them into a ranked list. The top of the list turned out to be the Polish alphabet.
You can point a Nominatim client at Mailwoman now and get a geocoder from a SQLite file, without PostgreSQL or a planet import. We did, and the US worked beautifully while the rest of the world resolved to its American namesake. The bug was one line: we'd told it the answer was always America. This post covers the line, the four cities that still won't move once you delete it, and the ranking database we forgot to switch on — which faked the entire scoreboard until a contradiction gave it away.
We ran our 30 MB browser geocoder against the incumbents — Nominatim and Pelias — on real European addresses, scored the direct way. We'd won the US. Europe opened with a double-digit loss. The cause was silence: on messy addresses we returned no result at all. This post covers what caused the empty results, the three fixes that took us clear of both incumbents in Europe, and the one place — Australia — we've now diagnosed but not yet closed.
Our parser scores 28% on Spanish addresses by the metric that grades its labels. By the metric that grades where the address lands on Earth, it's within a couple of kilometers. Same model, same addresses. Only one of those numbers is measuring the thing we ship.
We injected a postcode's country signal straight into the model, and German addresses jumped thirty-five points. Then three retrains taught us the same anchor can't help an address written in the other order, because it never learned to find the city. It learned which way to look.
We taught a resolver to drop a postcode into the city polygon that contains it. Japan has no city polygons, so we resolved it another way and hit 94%. Then Korea let us nail the coordinate every time and refused to give up the name — and the gazetteer is the reason.
We thought a postcode was a strong enough signal to delete a configuration flag. Then we measured it. A five-digit code pins its own country less than half the time — and that number talked us out of writing the code we were about to write.
Japanese addresses run backwards: prefecture, then city, then block, then number. They have no street names. Wepulled 6,373 of them from Who's On First.