Consider a Mastodon/Fediverse handle, like @username@domain

[mcc@mastodon.social]

Consider a Mastodon/Fediverse handle, like @username@domain.example . What kinds of restrictions are there on "username"? Can I assume any valid unicode could go in there?

[tiff@xn--lw8h.xn--9s9h.it.com]

@mcc not emoji. not because of anything I can find in the activitypub spec but because mastodon doesn't forward notifications if there's emoji in the recipient address.

[mcc@mastodon.social]

Somebody linked me RFC 7565, which linked to RFC7564, and if that's the place to look this appears to be the list of disallowed characters in a Fediverse username, and I'm cracking up because it's *mostly* stuff you'd expect, except the very first category of banned characters, specially, is "pre-1700 Korean characters".

The fediverse is welcome to all. EXCEPT KOREAN TIME TRAVELERS. Did you just wake up from being frozen in ice during the Joseon dynasty? The IETF is targeting you PERSONALLY

[xgranade@wandering.shop]

@mcc I get it, but the exclusion of "Q" property characters is an interesting and odd one.

[julian@fietkau.social]

@mcc In practice, it varies a lot. In theory, I have seen different people come to different conclusions based on the RFCs involved.

Related discussion:
https://github.com/swicg/activitypub-webfinger/issues/9
https://shkspr.mobi/blog/2024/02/internationalise-the-fediverse/

[tiff@xn--lw8h.xn--9s9h.it.com]

@mcc well, darn, I guess I don't comply to the PRECIS IdentifierClass profile

[evan@cosocial.ca]

@mcc unfortunately, it's very restrictive. It feels like a huge opportunity for us to reach the majority of people on the planet who use non-Latin characters for their names, but the network right now is mostly Latin.

https://www.w3.org/community/reports/socialcg/CG-FINAL-apwf-20240608/

[evan@cosocial.ca]

@julian @mcc it's a good discussion!

[nasser@merveilles.town]

@mcc I feel like I tried Arabic usernames and they didn't work

[thatdawnperson@toot.cat]

@mcc 왜 그렇게 되셨나요?

[mcc@mastodon.social]

@thatdawnperson I thiiiiink that the way they fit the antique Korean jamo into requires a really awkward hack that they just don't want these systems to have to deal with

[mcc@mastodon.social]

@thatdawnperson But seeing them lead with that just makes it seem oddly vindictive

[hearth@plush.city]

@mcc ...is there any reasoning given for this?? and for the latter two, those seem weird too
-F

[chrisamaphone@hci.social]

@mcc this was a subplot in Analog surely

[mcc@mastodon.social]

@chrisamaphone so remember, part of the revanchivist ideology in Analogue involved enforcement of writing in Hanja

[alilly@solarpunk.moe]

@mcc @Hearth @xgranade I'm guessing Q and R are disallowed to mitigate homoglyph attacks. Maybe Old Hangul too, which presumably contains some homoglyphs with modern Hangul.

[mcc@mastodon.social]

@alilly @Hearth @xgranade ohhhh wait that would make so much sense :O with the old jamo

[hearth@plush.city]

@mcc @alilly @xgranade that makes sense! homoglyph attacks are still possible with e.g. replacing latin o with greek ο or cyrillic о, though?

...unless that's what section Q is talking about, i don't know exactly what it means
-F

[alilly@solarpunk.moe]

@Hearth @xgranade @mcc … Damn, that might be a valid argument in favor of Han unification. How dare things I already made up my mind on have nuance I didn't consider?

[alilly@solarpunk.moe]

@mcc @Hearth @xgranade Yeah but that's much harder to do anything about, unless you want to ban modern speakers of languages written using Cyrillic from using names in their native language, which… don't do that.