Re: [ietf-smtp] Should we update an RFC if people refuse to implement parts of it ?

[Viktor Dukhovni <[e-mail]>]

On Thu, May 27, 2021 at 12:59:53AM +0800, Jiankang Yao wrote:

> > I recognize the distinction while also realizing that, as you know,
> > things often leak.  My recollection (if Jiankang is following this,
> > his memory is probably better than mine) is that the WG explicitly
> > discussed the issue and concluded that U-labels were a better idea
> > than A-labels.  
> 
> Yes, I think so. The EAI WG discussed this issue.  Section 3.7.3.
> Trace Information  encourages to use UTF-8 form.  One reason I think
> is that trace information will be put into header for human reading.

But, and this is crucial, the human reading the trace information is
rarely either the sender or the ultimate recipient of the message, who
are generally presented with a subset of the headers fields ("To", "Cc",
"Date", "Subject" ...).  Examination of trace headers is far more likely
to a task for a mail system administrator.  They're used in abuse
reports and the like, and a uniform representation is more important
than familiarity to the community of readers of some given language.

Mail system administrators don't necessarily read the same scripts as
their end users.  Mail system administrators would reasonably expect
the EHLO name recorded in trace headers to match the name received in
the actual EHLO command on the wire (and recorded in their email logs).

> UTF-8 is better for human reading.  A-label is ugly for human reading,
> but ok for machine reading.

Sure, if the text is Russian, some Latin-based alphabet or at a stretch
Greek, I can more easily distinguish one U-label string from another
than an A-label form like "xn--b1adqpd3ao5c.org", ... and yet I'd much
rather see A-labels in trace headers than Arabic or Chinese.  The text
in 3.7.3 is not something I'm inclined to implement.

Specifying the use of U-labels in the "from" and "by" clauses rather
looks like a bad judgement call, rough consensus or not.  Until the
Protocol Police show up, I'm sticking with A-labels. :-(

-- 
    Viktor.