Re: [idn] Dots, and a path to working IDNs

["D. J. Bernstein" <djb@cr.yp.to>]

Keith again complains that UTF-8 might not ``work well for some
important languages.'' I think it would be a complete waste of time to
discuss this; the world has settled on UTF-8. I again ask the WG chairs
to run a poll to see whether we have consensus that the long-term IDN
solution will encode Unicode characters as UTF-8 on the wire.

Keith Moore writes:
> So one way to prevent this ambiguity is to encourage applications 
> to refuse to accept domain names containing "bad" dots.  That way,
> there won't be any market for them.

Probably bad->good conversion is just as easy as rejecting bad names, if
the application is going to be upgraded anyway. The mere threat should
be enough to dissuade people from trying to use bad names.

> One difference may be in how we define what it means for IDNs to "work".

http://cr.yp.to/proto/idn.html: ``We want to let people use domain names
like ... (`alpha beta gamma dot com'). They should be able to register
the name, set up computers under the name, connect to those computers by
name, set up web pages under the name, set up links to those web pages,
browse those web pages given the name or a link, send email from an
address under the name, receive email at that address, etc.''

> Another difference may be in our assumptions about when and to 
> what extent people will be willing to upgrade their existing software.

The crucial advantage of the plan I've described is that we _don't_ have
to wait for massive software upgrades before deploying IDNs. We can take
advantage of widespread UTF-8 support in existing software.

If it turns out that users won't be completely happy without the slow,
painful nameprep-in-every-program updates, then nothing has been lost.
There won't be any transition problems, because bad IDNs won't exist.

---Dan