[cyxxon]

Small nitpick: the example "LATIN SMALL LETTER SHARP S (“ß” U+00DF) uppercases to the two-character sequence “SS”:³ Straße ⇒ STRASSE" is slightly wrong, it seems to me, as we now do actually have a uppercase version of that, so it should uppercase to "Latin Capital Letter Sharp S" (U+1E9E). The double-S thing is still widely used, though.

[mkayokay]

Duden mentions this: "Bei Verwendung von Großbuchstaben steht traditionellerweise SS für ß. In manchen Schriften gibt es aber auch einen entsprechenden Großbuchstaben; seine Verwendung ist fakultativ ‹§ 25 E3›."

But isn't it also dependent on the available glyphs in the font used? So f.e. it needs to be ensured that U+1E9E exists?

[NoInkling]

According to Wikipedia:

> "Since 2024 the capital ⟨ẞ⟩ is preferred over ⟨SS⟩."

https://en.wikipedia.org/wiki/%C3%9F

Check reference #5 and compare it to the older wording in reference #12.

[Kwpolska]

I don't think there exists any code that makes uppercasing decisions based on the selected font. Besides, if it doesn't exist in the current font, there's probably a fallback font.

[Muromec]

But what if you need to uppercase the historical record in a vital records registry from 1950ies, but and OCRed last week? Now you need to not just be locale-aware, but you locale should be versioned.

[pjmlp]

Lowering case is even better, because a Swiss user would expect the two-character sequence “SS“ to be converted into “ss“ and not “ß“.

And thus we add country specific locale to the party.

[account42]

Not just a Swiss user as there are many German words that use ss and not ß. And having an ss where there should be an ß will be a lot less disruptive as the inverse because people are used to ASCII limitations.

[Rygian]

The footnote #3 in the article (called as part of your quote) covers the different ways to uppercase ß with more detail.