https://en.wikipedia.org/wiki/Punycode -- it's a way to represent non-ascii TLDs in ascii.
So many people in every continent can't write their name or last name with just ascii.
https://xn--80abdhdaex8bfbbgpe2c.xn--j1amh/ (HN has translated it, but a forum for Ukrainian speakers wouldn't.)
That's what this system is for.