Re: [EAI] I-D Action: draft-ietf-eai-mailinglistbis-00.txt

[Frank Ellermann <[e-mail]>]

On 27 November 2011 01:22, "Martin J. Dürst" wrote:

>> I went back and looked at that section again.  (Excuse: it's from
>> Randy's old draft.)  The sentence in question says:

>>   Note that discussion on whether internationalized domain names
>>   should be percent-encoded or puny-coded, is ongoing; see<xref
>>   target="I-D.duerst-iri-bis" />.

> Why not just point to RFC 3986, last two paragraphs of section 3.2.2
> (http://tools.ietf.org/html/rfc3986#section-3.2.2)?

> That's an Internet Standard rather than an "ongoing discussion".

All those "<reg-name> outside of DNS" considerations in STD 66 are
IMO irrelevant for UTF8SMTPBIS addresses.  If that's correct we end
up with the last two sentences in RFC 3986 3.2.2:

| When a non-ASCII registered name represents an internationalized
| domain name intended for resolution via the DNS, the name must be
| transformed to the IDNA encoding [RFC3490] prior to name lookup.
| URI producers should provide these registered names in the IDNA
| encoding, rather than a percent-encoding, if they wish to maximize
| interoperability with legacy URI resolvers.

That is an ordinary MUST, and obviously the tool or party knowing
how it works cannot delegate "punycoding" to another tool or party
which might not know how it works.

-Frank