[brazzy]

> The correct use is to check whether a submitted identifier contains characters that visually mimic Latin letters, and if so, reject it

That is a really bad and user-hostile thing to do. Many of those characters are perfectly valid characters in various non-latin scripts. If you want everyone to force Latin script for identifiers, then own up to it and say so. But rejecting just some them for being too similar to latin characters just makes the behaviour inconsistent and confusing for users.

[wongarsu]

What would make sense is to have a blacklist of usernames (like "admin" or "moderator"), then use the confusables map to see if a username or slug is visually confusable with a name from that blacklist.

I initially thought that must surely be what they are doing and they just worded it very, very poorly. But then of the 31 "disagreements" only one matters, the long s that's either f or s. All other disagreements map to visually similar symbols, like O and 0, which you should already treat as the same for this check

Not to mention that this is mostly an issue for URL slugs, so after NFKC normalization. In HTML this is more robustly solved by styling conventions. Even old bb-style forums will display admin and moderator user names in a different color or in bold to show their status. The modern flourish is to put a little icon next to these kinds of names, which also scales well to other identifiers.

[orthoxerox]

The correct approach is to accept [a-z][a-z0-9]* as identifiers and forbid everything else.

[skrebbel]

Yeah fuck foreigners who want to be able to spell their own name right.

[tsimionescu]

In all cultures, there is an expectation that you have to provide a name for yourself that is intelligible to the culture you're interacting with, both in written language and in speech. If your name is Albert and you are going to interact with many Japanese speakers, you'll have to call yourself アルバート in writing and pronounce your name as something like "Ah roo bay toe" to fit in. If you have a name whose pronunciation depends heavily on tones, such as a Mandarin or Vietnamese name, and you are going to interact with speakers of a non-tonal language, you'll have to come up with a version that you're happy with even if pronounced in the default neutral tone that those people will naturally use. If your name is 高山, you'll have to spell it as Takayama.

Similarly, if you're going to create an identifier for yourself that is supposed to be usable in an international context, you'll have to use the lowest common denominator that is acceptable in that context - and that happens to be a-zA-Z0-9. Why the Latin alphabet and numerals and not, say, Arabic, you might ask? Because Chinese and Indian and Arabic speakers are far more likely to be familiar with the Latin alphabet than with each other's writing systems.

[skrebbel]

The article has examples about people naming themselves "Аdministrator". That's not about machine-readable identifiers, it's about display names. This entire subthread is either people missing that and thinking they're talking about login usernames and the likes, in which case I don't disagree, or people actually believing it's OK to limit people's screen names to a-zA-Z0-9 in which case I say, that's deeply imperialistic and a super shit thing to do.

[tsimionescu]

It depends on the intention. If this is about a unified international community, like a group of contributors to a Open Source Project, or like HN, then there is no reason to allow general unicode identifiers.

If the project is instead a more general solution intended for many independent communities that may well be country-specific, then yes, it should allow general Unicode display names. It should probably still help restrict this per community, so that a Chinese community doesn't get confusables with Japanese-only characters (though Han unification probably happens to protect from that), or a Cyrillic community doesn't get confusables with Latin characters.

[popcornricecake]

Is HN "deeply imperialistic and super shit" too? Or is it okay because there's no option to set a display name?

[diacritical]

I think restricting the allowed characters should apply to usernames and other unique identifiers that can lead to confusion (admin vs аdmin with a Cyrillic "а"). So if I write my name as "José", I should be able to make an account called "Jose" and still enter "José" in the name field, if such a field exists in the first place. Although I'm not even sure about this.

If you're saying that "José" should be accepted as an username, shouldn't "Борис" or "김" or "金" also be valid?

It makes sense to restrict the alphabet for things like usernames that should be unique, should be easy to read for security reasons and should be correctly handled by various types of backend software.

I'm not from the US and my name isn't ASCII, but I wouldn't mind spelling it with the English alphabet, even in a name field.

I also don't understand how English has 26 letters, but letters like "é" in "José" or "ï" in "naïve" appear as normal letters. And if I write "Jose" instead, it would read as offensive. In my language that uses Cyrillic, the letters of the alphabet are all the letters we use, period. It would just be wrong to borrow a letter from another alphabet, even if it's the same script, just because someone's name includes it in their language. I have a friend from a neighboring country that changed one of his Cyrillic letters when he came to my country. I would do the same if I went to his country and they didn't have a letter we have.

[kgeist]

For logins, we're already used to the fact that they're expected to be in Latin. Having them in the native alphabet is more trouble than it's worth (one system supports it, another breaks etc., easier to remember one, in Latin, across systems) I'd be irritated though if I couldn't use my native alphabet in the user profile for the first name/last name

[integralid]

>Please provide your name exactly as it is in your government documents.

>This is extremely important. Failure to comply will lead to termination of your service with no refund, criminal prosecution, our CEO calling you in tears and a hitman being informed about your last known location

...

Validation error: "First name" contains invalid characters.

[kgeist]

Heh, I had this exact thing when getting certified at Microsoft (remotely). They required me to enter my name exactly as it appears on my government ID (not a single Latin character), but their registration site... simply blocked any characters outside of Latin. I had to obtain an international travel passport to get the "official" transliteration of my name

[netsharc]

I've gotten a visa to a country that doesn't use Latin characters. My name got transliterated. At the bottom of the visa there's the machine-readable field that uses ASCII characters, and my name lost a character (a OU became just U).

[silon42]

As someone with non-ASCII name, I'd like a unicode whitelist (system wide if possible).

And special features to mark cyrillic or other for-me-dangerous characters.

[Zardoz84]

And you pissed off nearly half of the world population.

[paultendo]

I agree that rejecting valid non-Latin characters in valid contexts is user-hostile, but I should be clearer about scope: this is specifically about machine-readable identifiers (slugs, handles, ENS names) where the character set is intentionally restricted, not display names or user-facing text.

The approach there should be what wongarsu describes below (imo), to style the UI so official accounts are visually distinct (badges, colour, etc.) rather than policing the character set.

namespace-guard is deliberately opinionated for the slug/handle case where you've already decided the output should be ASCII-safe. If your use case is broader than that, confusables detection without rejection is the right call.