[eesmith]

Some places use an encoded lat/long.

Open Location Code - "Google has shown practical usage of plus codes for addressing purposes in Cape Verde,[10] parts of Kolkata[11] and Kolhapur[12] in India, and the Navajo Nation in the United States.[13]" - https://en.wikipedia.org/wiki/Geocode . https://freethoughtblogs.com/singham/2023/12/24/using-olc-co... says a friend of his sent an OLC coordinate to get to a place in Carmel-by-the-Sea, California, which (infamously?) has no street numbers.

What3words - "This population had "no consistent addressing system" until May 2016 when Mongol Post started using a geocoding system provided by what3words." - https://en.wikipedia.org/wiki/Mongol_Post

Over time (centuries?) the named coordinate will no longer be valid as the location is no longer near enough to that lat/long.

[midasuni]

I believe W3W are 1m squares, so in Japan it sounds like they may be already broken

[eesmith]

https://en.wikipedia.org/wiki/What3words says "What3words divides the world into a grid of 57 trillion 3-by-3-metre (10 ft × 10 ft) squares".

Australia moves about 7cm/year so after about 43 years a W3W coordinate no longer matches local coordinates.

It feels weird that a continent could move so much in someone's lifetime.

Looks like the 1906 San Francisco quake had displacements up to 8.5 meters, so more than two squares. https://en.wikipedia.org/wiki/1906_San_Francisco_earthquake