German sharp S uppercase mapping

[Dominikus Dittes Scherkl]

Am 02.12.24 um 11:19 schrieb Marius Spix via Unicode:
> That problem is not not new. The long ſ, which is only used in old Fraktur script, but not in modern Antiqua script, has the same issue. It shares its uppercase form S with the round s, which behaves differently than the Greek final Sigma ς and can appear mid-word, for example in compound words.
>
> For example: to_lower(to_upper("Hauſtür")) returns "Haustür", which is inaccurate.
>
> That can even make a difference, because "Werksirene" and "Werkſirene" or "Antragsteller" and "Antragſteller" have completely different meanings.

Yes, but at least the long ſ is not used in legal names (today). This is
the main source of problems. Otherwise, I am sure, we would now have a
new upper-case form of long ſ. :-)