Subject: [VCARDDAV] Internationalized email addresses in vCard 4.0

From: Simon Perreault <[email-masked]>
Date: Fri, 05 Nov 2010 09:55:32 -0400

Hello,

We need some advice from the EAI working group.

vCard 4.0 is a file format for contact information. It's a textual
format and its character set is always UTF-8. One of the information
items it may contain is email addresses. See here:
http://tools.ietf.org/html/draft-ietf-vcarddav-vcardrev-13#section-6.4.2

Basically to list an email address in a vCard you will have a line
looking like this:

EMAIL:[email-masked]

The ABNF for what comes after the colon is "addr-spec", which is defined
in RFC 5322, section 3.4.1.

Now, addr-spec does not allow full Unicode. An internationalized address
would need to be EAI/IDN-encoded, which implies that a vCard app would
need to decode it to display it to a user.

Questions:
- Is this the right way to do it?
- Should we allow full Unicode, which removes the need for decoding from
the vCard app and adds the need for encoding in the MUA?
- Should both forms be possible, should one form be preferred over the
other, or should only one form be allowed?
- What should the ABNF look like for allowing Unicode characters in
email addresses?
- Would it help us in any way if we were to specify a mailto: URL instead?

Thanks,
Simon
-- 
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vCard 4.0               --> http://www.vcarddav.org

---

From: Bjoern Hoehrmann <[email-masked]>
Date: Sat, 06 Nov 2010 01:03:10 +0100

* John C Klensin wrote:
>Except that you misunderstand what "EAI/IDN encoding". I would
>strongly suggest that you have a look at the EAI drafts and that
>you deal with this by replacing the 5322 addr-spec with the EAI
>equivalent.  Otherwise, you are just going to create trouble for
>yourselves and your users.

I haven't been paying attention for some time, but trying now, I could
not find that equivalent (I went to the Working Group homepage and
clicked through a couple of drafts, grepped the RFC index for "email"
and "e-mail", particularily scanned for some ABNF in RFC 4952, none of
which turned up anything useful within five minutes. Then I went to
Wikipedia, which only references RFC 5335 on "Internationalized Email
Headers" which didn't seem that relevant, but if you scroll way down
there, there is "utf8-addr-spec"; if that is the definition you mean,
then the definition does not really make sense to me; I would expect
e-mail addresses to be composed of characters, not sequences of bytes.)

I think it would be a good idea to have a Internationalized Email Ad-
dresses RFC that defines the syntax and semantics of addresses, and
does so in terms of characters, not bytes (and naturally does not de-
fine headers, mail protocol extensions, and so on). That specification
might then also address how other protocols are to use said addresses.
For what it is worth.
-- 
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Am Badedeich 7 · Telefon: +49(0)160/4415681 · http://www.bjoernsworld.de
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---

From: Simon Perreault <[email-masked]>
Date: Sat, 06 Nov 2010 12:11:30 -0400

John C Klensin wrote, on 11/05/2010 06:41 PM:
> I would

To be clear, does "the EAI equivalent" stand for uAddr-spec, as defined in
<http://tools.ietf.org/html/draft-ietf-eai-rfc5335bis-03#section-4.4>?

> Your one problem is that you will end up with a
> normative reference with a spec that isn't finished yet.  The
> good news is that I hope and expect to have it wrapped up well
> before the end of the calendar year.

Got it, thanks. We'll certainly be discussing this in our WG meeting...

Simon

---

From: John C Klensin <[email-masked]>
Date: Fri, 05 Nov 2010 18:41:44 -0400

--On Friday, 05 November, 2010 09:55 -0400 Simon Perreault
<[email-masked]> wrote:

> vCard 4.0 is a file format for contact information. It's a
> textual format and its character set is always UTF-8. One of
> the information items it may contain is email addresses. See
> here:
> Basically to list an email address in a vCard you will have a
> line looking like this:
> 
> EMAIL:[email-masked]
> 
> The ABNF for what comes after the colon is "addr-spec", which
> is defined in RFC 5322, section 3.4.1.
> 
> Now, addr-spec does not allow full Unicode. An
> internationalized address would need to be EAI/IDN-encoded,
> which implies that a vCard app would need to decode it to
> display it to a user.

> - Is this the right way to do it?

Nope.  See above.

> - Should we allow full Unicode, which removes the need for
> decoding from the vCard app and adds the need for encoding in
> the MUA?

No, and you are asking the wrong question.  See above.

> - Should both forms be possible, should one form be
> preferred over the other, or should only one form be allowed?

What "both forms"?

> - What should the ABNF look like for allowing Unicode
> characters in email addresses?

See above.  Your one problem is that you will end up with a
normative reference with a spec that isn't finished yet.  The
good news is that I hope and expect to have it wrapped up well
before the end of the calendar year.

> - Would it help us in any way if we were to specify a mailto:

Arggh.  Translation: certainly not unless you want to wait for
the EAI WG to finish its review of mailto, which has not really
begun yet.

     john

---

From: Yangwoo Ko <[email-masked]>
Date: Sat, 6 Nov 2010 09:57:45 +0900

Pleae refer to https://datatracker.ietf.org/doc/draft-ietf-eai-rfc5335bis/

On Sat, Nov 6, 2010 at 9:03 AM, Bjoern Hoehrmann <[email-masked]> wrote:

> _______________________________________________
> IMA mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/ima
>

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---

From: John C Klensin <[email-masked]>
Date: Sat, 06 Nov 2010 14:05:37 -0400

--On Saturday, 06 November, 2010 12:11 -0400 Simon Perreault
<[email-masked]> wrote:

>> strongly suggest that you have a look at the EAI drafts and
>> that you deal with this by replacing the 5322 addr-spec with
>> the EAI equivalent.  Otherwise, you are just going to create
>> trouble for yourselves and your users.
> 

Yes, with the qualification that, like all WG I-Ds, this is a
moving target and might change before it is approved.  I
wouldn't personally expect that, but you shouldn't take my
belief as a guarantee.

    john

---

From: Marc Blanchet <[email-masked]>
Date: Sun, 07 Nov 2010 07:42:09 +0800

be aware:
- RFC5335 is experimental
- rfc5335bis is a draft

if we do normative reference to draft, we will have a dependency and 
moreover, the draft may change after we are on the rfc queue.

related work: one other way is to make it as a general IRI. but IRI spec 
(RFC3987) is being revised in IRI wg.

Many specs are or will be in same situation regarding support of i18n in 
domain names, email addresses and IRI. However, vcard is probably one of 
the simpler case, since vcard is "just a file format", it does not 
involve resolution per se. So we might end up thinking of a simpler case 
(i.e. just support utf-8 for example) without all the considerations 
related to the support of idn, eai, iri. The burden will be on the 
application that will be processing the email address, that application 
would have to support idn/eai/iri... So maybe some words around that 
fact/situation/client of vcard application behavior might be enough.

Marc.

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