Re: [idn] WG last call summary

["Adam M. Costello" <idn.amc+0@nicemice.net.RemoveThisWord>]

I have removed ietf@ietf.org, iesg@ietf.org, and iab@isi.edu from the
Cc: list.  I assume that if they want to hear from me, they'll contact
me.

"D. J. Bernstein" <djb@cr.yp.to> wrote:

> I recently asked a simple question about how IDNA is supposed to work,
> from a programmer's perspective: under UNIX, if LANG is en_US.UTF-8,
> should the MH/NMH ``show'' mail-displaying program convert names from
> the IDNA character set to UTF-8?  Costello...ignored the question.

I ignored it because you had already asked the exact same question using
"dig" instead of "show" and I'd already answered that question.

It's easy to see that no matter what we do, things will break:

For a long time, domain names have in practice contained only ASCII
characters.  There is bound to be software that breaks when fed
non-ASCII domain names.  If a program outputs non-ASCII domain names
that are fed to unprepared software, things will break.  If a program
encodes non-ASCII domain names using ASCII characters, and those
encoded names are seen by humans, that is another form of breakage.
Programs can often guess which form of output is preferrable, but as
you correctly point out, they cannot always know for sure.  Therefore,
there is no way to completely prevent breakage, except to stick with
ASCII-only domain names.

If this were considered a show-stopper, the working group could have
conceded defeat and disbanded long ago.  Instead, it chose to push
ahead and attempt to minimize (not eliminate) breakage and maximize
interoperability and incremental deployability.

I probably shouldn't have bothered to write this.  It's not really
constructive, and we've been over all this before.  Don't count on me to
return your next volley.

AMC