Re: [idn] The layers and character handling in DNS

[Patrik Fältström <paf@cisco.com>]

At 11.16 -0500 01-02-18, John C Klensin wrote:
>  > > (1) The IETF is NOT a forum where we have the knowledge on
>>  making a decision whether a mapping function is good enough or
>>  not for characters. The only thing the IETF can do is to choose
>>  someone which works in this area and trust them doing an as
>>  good job as possible. UTC is doing a good job, but they have
>>  "bugs" and problems with their mapping tables (as anyone would
>>  have) and we in the IETF will inherit them -- for good and for
>>  bad.
>
>Agreed.  But that implies, as above, that we make _zero_ of our
>own rules.  If the Nameprep document is more complex than "take
>the UTC rules and apply them" (perhaps in some specific order
>relative to other things that need doing), I think we are out of
>this space and into applying our own judgement... we I think we
>agree we should not do.

I agree with this in principle, BUT, we need still some extra text.

This because we might want to

- prohibit some code points as part of a label (compare with the 
problems with having no definition of what is a hostname compared 
with definition in DNS protocol to be able to handle decimal values 
of 0-255 (inclusive) as part of a label).

- specify what should happen with non-assigned characters (which 
solves the versioning problem).

- specify in what order case folding, normalization etc should happen.


    paf