Q1 is mapping on lookup permanent or transitional?

[John C Klensin]

--On Wednesday, April 01, 2009 09:07 -0700 Erik van der Poel
<erikv at google.com> wrote:

>...
> On the other hand, although you didn't ask about
> registration-side mapping, I find it ridiculous to attempt to
> forbid mapping on that side. It is up to the registrars and so
> on to come up with their own UIs. We have no say in that
> matter.

Depending on how one looks at it, you have either just come up
with another variation of "we don't care what you do before the
putative label gets into the protocol" --the "local mapping"
that you have argued against in other contexts-- or are making a
different version of the suggestions others have made about
stacks and/or pre-protocol mapping.

To the best of my knowledge, no one has ever suggested that
registrars cannot design their own UIs, that environments in
which Unicode is not native must be forced to use Unicode, or,
for that matter, that a would-be registrant who believes "up" is
actually "down" has to get over that belief.

In that regard, there is no protocol-visible difference between
IDNA2003 and IDNA2008.  From a descriptive standpoint, IDNA2003
doesn't discuss those issues at all  (some might even say that
it tries to pretend that they don't exist) while the IDNA2008
attempted to recognize them, note that different practices were
appropriate to, and used in, different environments, and then
move on.  The text that tried to do that upset enough people
(including, IIR, you) that it has now been removed.  But, in its
absence, you now believe the text is telling registrars how to
design their UIs. 

If we support mapping at all, the current state of the IDNA2008
specs are trying to do one thing on the registration side that
is new, and that is to try to insist that the registrant
actually understand what is being registered, i.e., that the
registrar (if there is one and the registrant directly if not)
present the registry with either a U-label or an A-label or
both, fully validated.  If the registrar wants to accept EBCDIC
as part of the process or getting to that U-label and verifying
it with the user, that really isn't our concern.

Please suggest what you think would be an appropriate
explanation of this; I'm running out of ideas.

    john