AW: sharp s (Eszett)

John C Klensin klensin at
Mon Mar 10 18:17:25 CET 2008

--On Sunday, 09 March, 2008 17:34 +0100 Georg Ochsner
<g.ochsner at> wrote:

> I personally do not think at all that "everybody" would expect
> two German words to match where sharp and double s are
> transposed. 

For the record, I didn't assert that was true and, partially
because I was aware of some of the examples you give, was never
convinced.  It was, however, what the IDN WG was told, either
directly in that form or because, as Mark pointed out, Unicode
casefolding makes them equivalent.

>As I said before the opposite is the case,
> changing sharp s into "ss" and vice verse can even lead to
> words with different meanings. At least it will lead to wrong
> spelling, and I hope nobody working on standards finds this a
> trifle.

Understood.  And I certainly do not.   We should all remember,
however, that there has never been a firm commitment that the
DNS could represent all relevant "words" (in either the ASCII or
IDN forms).   Some things are just not going to be possible to
distinguish.  Eszett is not one of them -- as I've said before,
we know how to support it although, for backward-compatibility
reasons, doing that now is likely to be somewhat painful.


best regards,

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