German sharp S uppercase mapping

[Jules Bertholet]

Hello all,

Traditionally, the capital form of the German sharp S (U+00DF ß) was 
"SS". More recently, a capital sharp S (U+1E9E ẞ) was added as a 
secondary alternative, but U+00DF’s uppercase mapping was left 
unchanged.

However, it seems that official German orthography, as of 2024, now 
considers ẞ to be the preferred uppercase mapping, with SS as the 
secondary alternative. From 
<https://www.rechtschreibrat.com/DOX/RfdR_Amtliches-Regelwerk_2024.pdf> 
page 48:

 > E3: Bei Schreibung mit Großbuchstaben ist neben der Verwendung des 
Groß buchstabens ẞ auch die Schreibung SS möglich: Straße – 
STRAẞE – STRASSE.

e.g.

 > E3: When writing in capital letters, in addition to using the 
capital letter ẞ, it is also possible to write SS: Straße – 
STRAẞE – STRASSE.

However, changing U+00DF’s uppercase mapping from SS to U+1E9E at 
this juncture would violate Unicode’s case pair stability guarantee.

I am not a German speaker, and have no opinion on what, if anything, 
should be done about this. But I thought it best to raise the issue for 
discussion.