Registry restrictions (was: Re: Domain names with leading digits (Re: Determining the basic approach))

[Paul Hoffman]

At 1:12 PM -0400 5/5/08, John C Klensin wrote:
>	* There will be things that cannot be done strictly in
>	the protocol that are, nonetheless, important.  We hope
>	that they can be handled by registry restrictions and
>	believe that registry restrictions (heavyweight or
>	lightweight and independent of the methods used) are an
>	important part of the picture, not just desirable.
>
>	* There will be things that cannot be done strictly by
>	registries that are, nonetheless, important.  We hope
>	that they can be handled by protocol provisions (at
>	registration time, lookup time, or both) and believe
>	that such protocol provisions are an important part of
>	the picture, not just desirable.
>
>	* So, even though we are not, in general, prepared to
>	tell registries what provisions and restrictions they
>	should (or must) apply, we believe that some things are
>	better done by registries than by protocol.
>
>	* We also believe that there are some things that
>	dangerous or treacherous enough, or that raise long-term
>	issues that are potentially problematic enough, that
>	they have to be checked in the protocol, not just left
>	to registration-time activity.  The most important
>	example of this involves characters that are invisible
>	out of context, notable the joiners, but we believe that
>	special measures for unassigned and disallowed
>	characters are also in order.
>
>That obviously leaves three sets of questions for the WG:
>
>(1) Is that model reasonable?

Yes, definitely.

>(2) What very specific things should be pushed off to the
>registries (remembering that "registry" equals "any zone in the
>DNS") and which ones left in the protocol (at registration time,
>lookup time, or both)?

Longer discussion. I believe that "which labels can appear to the 
left or right of a particular IDN label" is appropriate for that, but 
could be wrong about that.

>(3) For any given thing we try to push off to the registry, are
>we offering advice or do we think we have some leverage on
>telling registries what they "MUST" do?

The former, only. We can't force anyone to do anything.