Null Island is an inside joke among cartographers: an imagined island situated at 0° latitude, 0° longitude, where maps suffering from data glitches point themselves. If your map is centred on Null Island, something has gone wrong. So of course mapmakers have been having some fun with it—after all, it’s not something you could stumble across by accident. In a blog post, Alan McConchie of Stamen Maps delves into the lore and history of Null Island and its status as an Easter egg on the Stamen Maps platform, where it takes the shape of the island from the Myst game.

(As an update to my 2016 post on Null Island: Alan reports that the buoy at 0°, 0° has ceased to be. Also, the Null Island website, complete with flag, has moved here.)

W3W maintains that their algorithm keeps similar combinations “so far apart that an error is obvious. We also worked hard to remove homophones and near homophones like sale and sail.” They rate the the chance of two confusing combinations appearing close enough to be unclear at about 1 in 2.5 million. But in a new analysis of the algorithm, currently in preprint, computer scientist Rudy Arthur argues that despite W3W’s claims this chance of confusion is far higher, and warns against adopting W3W as critical infrastructure (it’s used by emergency services, particularly in the U.K.) without testing and comparing against available alternatives. [The Register]

Previously: What3Words Hasn’t Had the Greatest Couple of Months: A Roundup.

It’s also been the subject of several parodies, including what3emojis (emojis instead of words), Four King Maps (four swear words, UK and Ireland only on account of a lack of swear words, which frankly disappoints me) and Maps Mania’s own April Fool’s joke for this year, what2figures, which expresses any point on the globe in just two numbers (I’ll wait).

But more recently it’s come under criticism for having similar sounding word combinations for addresses only a few miles apart: see Andrew Tierney’s blog post (which expands upon this Twitter thread) and What3words’s response. This is especially a problem for first responders trying to locate someone who may have misspoken or mistyped their location, or because of their accent, resulting in rescue teams being sent to the wrong location.

Previously: Null Island.

Zero degrees longitude, zero degrees latitude is literally nowhere: situated in the middle of the open ocean, off the coast of Africa in the Gulf of Guinea, the only thing to mark its presence is a weather observation buoy [via]. But it’s also a significant set of coordinates, in that it’s the location you might get in the case of geocoding errors.

Hence the invention of Null Island, an imaginary place to flag geocoding failures. It shows up in version 1.3 of Natural Earth, for example, as an island one square metre in size, but coded so that it would never appear in an actual map. Gary Vicchi explains Null Island in more detail. As is the way of fictional places, Null Island has grown in the imagination: it has its own website, replete with sections on its history, geography, people and economy, and its own flag.