Comment 7 for bug 650498

Not implementing U+1E9E ẞ as a capital letter sharp s is rather radical.

In Unicode U+1E9E ẞ has for lowercase U+00DF LATIN SMALL LETTER SHARP S
But U+00DF ß has no defined uppercase.

This means uppercasing strings like "Maße" will usually give "MAßE".
Some software might give a different uppercase (with SS, SZ, or ẞ), but that's their choice (it could be a locale preference or a user preference).
On the other hand U+1E9E ẞ has U+00DF ß defined as its lowercase, so lowercasing "MAẞE" will always give "Maße".

In orther words, people who don't want to use U+1E9E ẞ are not forced to.

Refusing to implement U+1E9E ẞ as a capital sharp s, does not protect people who don't want to use it, but it is preventing people who might want to use it with its defined purpose. That character won't change the way most people write in German, but it is greatly useful to people who wish to use it.

Why can't users be free to decide what's idiotic or incorrect. Obviously it made in Unicode, so not all the experts agree it is incorrect. The proposal to encode it in Unicode was made by DIN (the German Standardization organization), they surely know what they are doing.

Please read http://std.dkuug.dk/jtc1/sc2/wg2/docs/N3227.pdf for a solid rationale to include the character with the intended form.