German sharp S uppercase mapping

[Giacomo Catenazzi]

On 2024-11-25 20:50, Steffen Nurpmeso via Unicode wrote:
> Jukka K. Korpela via Unicode wrote in
>   <CAGHxYa7QmmU=CcxudEzBmCk1xei7xESzQAn1dJ-JHbp_-UtWjA at mail.gmail.com>:
>   | Steffen Nurpmeso via Unicode (unicode at corp.unicode.org) wrote:
>   |
>   |>  i have SpecialCasing.txt from 2019, 13.0.0
>   |> says the file, and there one can read
>   |>
>   |>   # The German es-zed is special--the normal mapping is to SS.
>   |
>   |The current version of the file has the same text.
>   |
>   |I think it would be adequate and sufficient to replace the words ”normal
>   |mapping” to “default mapping in Unicode”. This would clarify that such a
>   |mapping is what Unicode specifies as the default. Whether it is the “normal
>   |mapping” depends on how “normal” is defined.
>
> Sigh, maybe i was mistaken with Switzerland, says wikipedia.  I am
> too lazy to get up and look into the Duden.

Yeah, Switzerland do not have the es-zed: we have "Strassen", so also no 
need of its upcase.

Some old signage may use it, but also other "modifiers" (like the the 
macron on consonants), which probably should also be treated in a 
special way for uppercase (and sorting). But possibly there is no fix 
rule (language, region, epoch).

In any case, I do not think we should rely too much on stability 
guarantee, or better: it is necessary for Unicode (especially 
normalization), but cases are almost formatting things, and so I think 
they may need to be adapted in a display stage, with more information 
(than Unicode could deliver), and for sure not stability (rules and 
expectation changes).

giacomo