RE: [idn] stringprep comment 1

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

At 1:53 PM -0800 2/1/02, Yves Arrouye wrote:
>  > >But they *are* allowed because the Server S uses Nameprep-08!
>>
>>  I'm misunderstanding your scenario then. You said in nameprep-08,
>>  character U+XXXX has a "deleting mapping". I understood that as
>>  "character U+XXXX is now assigned but is prohibited". If that's not
>>  what you meant, please help me.
>
>I meant that Nameprep-08 maps the codepoint out (to reuse the language in
>Nameprep). Let's say because this codepoint is a new variant selector,
>another zero-width thingamagic, whatever.

OK, then I did understand what you were saying, but I don't 
understand the problem. You originally said:

The interesting scenario is: Server S is on Nameprep-08 (where a deletion
mapping has been introduced for codepoint U+XXXXX), Client A is on
Nameprep-07 but his OS supports Unicode 4.0 and its IME generates U+XXXXX.
Client A will then pas U+XXXXX unchanged (since it was unassigned when
Nameprep-07's tables were generated) and Server S won't find a match, since
its stored strings do not have U+XXXXX.

Client A sends out a character that will never match something that 
could be stored in a name server under -07 (because it is unassigned) 
or under -08 or later (because it is mapped to nothing). Why would 
you expect the server to ever match it? What is the problem here that 
you see and that I don't?

--Paul Hoffman, Director
--Internet Mail Consortium