And what's magic about one meter? Latitude and longitude can be arbitrarily precise. But whatever. You want 40 million? Well, 360 degrees / 40 million ~ 10^-5. That's easily handled by "43.63872, -116.24135".
- Circumference of earth = 40,075 km
- Granularity needed = 3 meters
- Number of common words in dictionary (generous) = 60,000
- Number of bits needed for single axis = log((40075 km)/(3 meters))/log(2) = 24 bits
- Number of bits needed for two axis = 48 bits
- Number of bits given by a single word = log(60000)/log(2) = 15.8
- Number of words required for two axis = ceil(48/15.8) = 3
Also, keep in mind, 60,000 words is generous; this many words would probably include lots of archaisms. For comparison, 1password uses 18,000 words in its dictionary. You could probably shave off some bits by getting rid of slices from the north/south poles. You might also save space by ignoring parts of the ocean, but then it starts getting non-trivial.
If you want to make gibberish word like objects it's probably possible.
If they were always the same two (or three) words, fine.
But if there are multiple such encoding systems, any set of three words (foo.bar.baz) is ambiguous. Because it depends on the system being used.
So sure, someone might remember "foo.bar.baz". But "foo.bar.baz" in W3W might be in SF. But in Hanoi by some other system.
And then we get to the need to pay W3W to generate those codes. That's crazy bullshit.
And because it's pairs are increasing in area, I can state that I live in IO93 and it narrows it to:
https://www.karhukoti.com/maidenhead-grid-square-locator/?gr...
or I could give the next 2 characters to narrow it to a 1km x 1km (roughly) area that covers my town, or the 2 letters and 2 numbers that give a small area that pinpoints 2-3 houses on my street.
It's not really any more complex or hard to remember than a standard postal code or zip code.
If you are using 2 angles, I guess the place to start is with the circumference of the earth, which is 40 million meters. So to get within a meter, you then need to encode your angle with enough precision to indicate a single one of the 40 million possibilities.