Re: [idn] nameprep vs. stringprep

[Paul Hoffman / IMC <phoffman@imc.org>]

And, as folks can see on the list, the drafts with the tables moved 
have been published.

As far as we know, there is literally no change for the IDN WG with 
these new drafts from the previous ones. The exact same characters 
are mapped and prohibited. If we made a mistake in this, by all means 
let us know.

The only significant change that will affect other WGs that use 
stringprep is that only Unicode normalization form KC is specified. 
Our thinking is that if we specified both NFC and NFKC, we would need 
many more tables and there is a much higher chance of error. No one 
has given a strong argument for using NFC, other than objections to 
some of the mappings in NFKC, which cannot be changed by the Unicode 
Consortium without breaking a lot of deployed software. If other 
working groups want us to allow NFC and create and check the 
additional tables, we will probably hear about it during IETF last 
call.

--Paul Hoffman, Director
--Internet Mail Consortium