Many people won’t know this, but .ai is a domain name/extension for Anguilla - a country probably many don’t even know exists. Anguilla is a small Caribbean island nation. Their economic expansion has been fueled by luxury tourism, offshore finance, and lobster fishery. Their domain of ai is managed by Offshore Information Services and anyone can register under this domain for a minimum of two years, meaning it doesn’t have any other special requirements aside from finding a domain registrar that actually offers this service.
While Google does not consider the ai domain extension to be generic, meaning it is always directed at Anguilla, it has been embraced by registrants working in the field of artificial intelligence since it has become a very popular field.
I think that it is a lesser-known fact that the vast majority of online domain registers can't actually provide this service for many countries in the world. There are only a handful of services that will help you register a ccTLD that is difficult to obtain due to many different factors. I probably had the best experience with Nominus because they are one of few that can actually provide ccTLD services worldwide and the whole registration process is very easy.