I think the lesson here would be using only ordinary characters in domain names (then what HN does would not matter), if you (and I mean anyone, not you in particular) advertise domain with special characters people will be confused because some companies advertise domain with special characters while you should actually read it with normal characters and not literally plus there is quite a stigma that these special characters are used for malicious purposes to pretend they are different sites. Dunno what's situation in Germany but here in Czechia where we also widely use special Latin characters in language, but they are pretty much non existent from domain names, though sometimes you can see them and they mean you should strip the domain name in your head and type it without special characters.