Q2: What mapping function should be used in a revised IDNA2008specification?

[Alexander Mayrhofer]

(again, sorry for the late reply, and potentially ignorance for any
discussion that i missed) 

> What characters should be mapped into what other characters in a  
> revised IDNA2008 specification?

I'm speaking from a perspective of a registry primarily using german
script. Therefore, we're primarily concerned about case folding, which
should be covered by standard Unicode case folding tables. We have
issues with the "sz" "sharp s" problem, because the "sharp s" appears in
many german words, but that's a problem that we share with our esteemed
german colleagues.

> Can we describe succinctly and precisely what these mappings 
> are? How?  
> What should they be?

As described above, for scripts that we care about, Unicode case folding
tables should do. Don't get me started on the "capital sharp s",
please...

Alex