Divvying up Earth’s surface into nine-metre-square blocks requires nearly 57 trillion addresses (to be precise, 56,764,364,951,858 of them). That sounds a lot, but Mr Sheldrick realised that 40,000 words would be enough to do the job—indeed, more than enough, since that number actually yields 64 trillion three-word combinations. Moreover, places that are at sea have only English addresses. The other languages, restricted to the land, thus require a mere 25,000 words each. When drawing up a list in a new language, What3Words’ linguists toss out homophones, and also any words that may create offence, such as “fondle”, in English, or, in Arabic, words for alcoholic drinks. Otherwise, words are selected based on their familiarity and frequency of use.