comments on defs -- definition of "IDN"

[John C Klensin]

I've tried to reflect Andrew's 24 July comments in the latest 
version of "Defs", although possibly not quite as he expected, 
which will be posted later today.  There is one of them that 
represents a possibly-significant change which I cannot deal 
with without advice from the WG.  In particular:

--On Friday, July 24, 2009 9:53 AM -0400 Andrew Sullivan 
<ajs at shinkuro.com> wrote:

> 2.3.2.3
>
>    An "internationalized domain name" (IDN) is a domain name
> that may    contain any mixture of NR-LDH-labels, A-labels, or
> U-labels.
>
> This entails that www.example.com is an IDN: it contains three
> NR-LDH-labels, which meets the "any mixture" rule, since one
> possible mixture is "none".  That might be surprising to some
> people.  What about
>
>    An "internationalized domain name" (IDN) is a domain name
> that    contains at least one A-label or U-label, but that
> otherwise may    contain any mixture of  NR-LDH-labels,
> A-labels, or U-labels.

The original version of IDNA took the position that the set of 
IDNs consisted of all labels that were valid under the LDH rule 
plus all labels that were acceptable to IDNA.  In other words, 
"IDN" was a superset of "fully-qualified domain name all of 
whose labels were in LDH form".  The current text in 
Definitions, cited above, is consistent with that historical 
definition.   I agree with Andrew that it is confusing, but 
suspect that a change at this point would result in even more 
confusion and possibly some errors.  So I haven't changed it, 
but am open to direction from the WG.