Concordances are a good place to start since we’ve already mentioned other gazetteers. Put simply: We want to hold hands with as many other gazetteers – past present and future – as possible.

There is more than enough room for multiple gazetteers in the world and the point of a concordance is only to be able to say, for example, that “our Boston” is the same as “their Boston”. The details of either one of those records may be entirely different because of an individual organization’s focus or perspective. Multiple outlooks on the same subject are a good thing. Concordances allow everyone to work on the things that are important to them while still being aware and acknowledging the work that others are doing and provide a mechanism for all that work to hold hands.

Every WOF record contains a property called wof:concordances which is a dictionary of simple key/value pointers to the identifiers of the same in other databases. For example:

"wof:id": 101736545,
"wof:concordances": {
  "fct:id": "03c06bce-8f76-11e1-848f-cfd5bf3ef515",
  "gn:id": "6077243",
  "gp:id": "3534"

As of this writing we have concordances for things from GeoNames (159, 359 of them), GeoPlanet (135, 399 of them), QuattroShapes (115, 550 of them), Factual (80, 973 of them), a variety of airport codes (ICAO, IATA, FAA and OurAirports), Wikipedia pages (just for airports right now) and even concordances for Mapzen Border countries. Soon, we will have more.