Allowing only a few alphabets doesn't solve much (Cyrillic "а" still looks like latin "a" in most fonts) but opens new cans of worms: how do you update this list, why isn't alphabet x of important minority y included, etc.
Much easier to just allow everything in the technical standards and let domain registries set reasonable standards that make sense for that tld. Sometimes that works well (.de for example has a list of 93 allowed unicode characters [1] which covers everything a German might plausibly use from German or neighboring country's alphabets), but some registries just don't seem to care much (e.g. .com).
Much easier to just allow everything in the technical standards and let domain registries set reasonable standards that make sense for that tld. Sometimes that works well (.de for example has a list of 93 allowed unicode characters [1] which covers everything a German might plausibly use from German or neighboring country's alphabets), but some registries just don't seem to care much (e.g. .com).
1: https://www.denic.de/en/know-how/idn-domains/idn-character-l...