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Re: IDNA reference

From: John C Klensin <john-ietf@jck.com>
Date: Tue, 07 Sep 2010 11:06:01 -0400
To: Wil Tan <wil@dready.org>, Julian Reschke <julian.reschke@gmx.de>
cc: public-iri@w3.org
Message-ID: <A083BE6E4A83E40B22CF5A59@[]>

--On Tuesday, September 07, 2010 10:14 PM +1000 Wil Tan
<wil@dready.org> wrote:

> On Tue, Sep 7, 2010 at 7:41 PM, Julian Reschke
> <julian.reschke@gmx.de>wrote:
>> Hi,
>> <http://tools.ietf.org/html/draft-ietf-iri-3987bis-01#section
>> -3.4>:
>>   Replace the ireg-name part of the IRI by the part converted
>>   using the ToASCII operation specified in Section 4.1 of
>>   [RFC3490] on each dot- separated label, and by using U+002E
>>   (FULL STOP) as a label separator, with the flag
>>   UseSTD3ASCIIRules set to FALSE, and with the flag
>>   AllowUnassigned set to FALSE.  The ToASCII operation may
>>   fail, but this would mean that the IRI cannot be resolved.
>>   In such cases, if the domain name conversion fails, then
>>   the entire IRI conversion fails.  Processors that have no
>>   mechanism for signalling a failure MAY instead substitute
>>   an otherwise invalid host name, although such processing
>>   SHOULD be avoided.
>> In August, RFC 3490 has been obsoleted by RFC 5890/91.

And there is no "ToASCII" operation any more, so any such
sentence will need rewriting, not just an updated reference.
"Producing A-labels" (below) is better terminology.

Actually, 5890/91/92/93 and arguably the still unpublished RFC
5895.  RFC 5894 is not normative, but contains the explanations
that might be more useful to some people as well as a discussion
of the transition issues.

>> What's the right reference for ToASCII now?

> The closest thing would be sections 5.1 to 5.5 of RFC 5891,
> but simply referencing them will lead to incompatibility (e.g.
> producing different A-labels from the IDNA2003 version.)

We have been recommending saying something like "... IDNA as
described in RFC 5890 and the companion documents to which it

> http://unicode.org/reports/tr46/ details a good transition
> strategy, but I wonder how one could work that into iri-bis.

TR46 (which is not yet a stable reference since the text is
still under review and may change yet again), details a
transition strategy.  But it is one that does not have IETF
consensus, partially because it posits a much slower transition
to allow for circumstances that are either very low frequency or
that represented abuses even under pre-IDNA2008 standards and
best practices.   Let's not make things more confusing by trying
to reference it as if it were the only reasonable approach to
the situation.

Received on Tuesday, 7 September 2010 15:06:43 UTC

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