@0x0 I voted for "Alphanumeric Unicode character", but I also think that it would make sense to make the non-ASCII character support optional behind an opt-in admin config, since there would certainly be a compatibility hazard that normal admins may well want to avoid, although providing an option for adventurous admins at their own risk might be fine.
@0x0 I don't believe "Any Unicode character" would be conformant to the standards. RFC 7565 (The ’acct’ URI Scheme) is clear about it:
> Before applying any percent-encoding, an application MUST ensure the following about the string that is used as input to the URI-construction process:
> o The userpart consists only of Unicode code points that conform to the PRECIS IdentifierClass specified in [RFC7564].
https://datatracker.ietf.org/doc/html/rfc7565#section-6
の投稿
0x0@corteximplant.com
このアカウントは、notestockで公開設定になっていません。
@SynAck @0x0 How would that be different from non-username Unicode texts like the display names?
Perhaps the lack of `lang` attribute would not be quite helpful for assistive technologies, but restricting the string to ASCII characters doesn't help either IMO. For example, VoiceOver in Japanese locale would read the ASCII usernames in a very clumsy accent as if it were reading a romanized Japanese text (well, which makes sense if the username is actually a romanized Japanese text, and the AT cannot reliably determine whether that's the case or not).
@SynAck @0x0 I even imagine that usernames in language-specific writing systems, e.g. Chinese characters, might be more friendly to automatic language detection.
Of course, explicit support for `lang` attribute in usernames would be desirable, but I also imagine that adopting non-ASCII characters might motivate protocol extensions like `preferredUsernameMap` (<https://github.com/w3c/activitypub/issues/395#issuecomment-1779587928>) for language-tagging usernames.
Remove `lang` attribute from individual statuses by Gargron · Pull Request #12124 · mastodon/mastodon
https://github.com/mastodon/mastodon/pull/12124
2019年10月のコミット。マジか
まあ実際に自動検出は誤りも多いし、そもそも投稿の言語タグは単一の投稿に複数の言語が混在している場合に対応できないから、検索用のヒントに留めるというのも分からないでもないけど……
Add lang tag to timeline posts for screen readers · Issue #18542 · mastodon/mastodon
https://github.com/mastodon/mastodon/issues/18542
スクリーンリーダに関する疑問に答えられていなくないか……？
