Unicode 5.2 -> 6.0

[John C Klensin]

--On Friday, October 15, 2010 10:22 -0500 Pete Resnick
<presnick at qualcomm.com> wrote:

> On 10/14/10 4:01 PM, Mark Davis ☕ wrote:
>> The stability of domain names is far more important -- that
>> once a  domain name is valid, that it remain so.
> 
> So I wish to disagree with the above statement and therefore
> *disagree* with the suggestion that we adopt (c) adding U+19DA
> to G. I am in favor of (a).
> 
> We made a design decision in IDNA2008 that domain names that
> contained other than some small set of letters, digits, and a
> small set of punctuation were more trouble than they were
> worth. We made it clear to folks that acceptable domain names
> should only contain certain classes of characters. What I take
>...
> The day that LATIN SMALL LETTER I changes class, I'll be happy
> to put something in category G. This is not that day.

Pete,

To reinforce this from a slightly different perspective, we
really want people to create domain name labels because the
strings have some mnemonic significance for them.  If, instead,
someone puts a character in a string because they found it
somewhere, thought it was cute, or wanted to play games with an
edge case, I don't think we should warp our general rules to
keep them amused.

If someone was actually using a New Tai Lue character, the
assumptions of the standard are such that it is rational for us
to assume that they actually understood the script and the
characters in it.  That implies that they would have known
perfectly well that U+19DA wasn't a numeral even if it took the
Unicode Standard until 6.0 to catch the problem and make the
correction.  

We never said it explicitly, but perhaps one of our criteria
should be that we are not obligated to keep labels that violate
the principles of the standard stable when it is discovered that
the violations are based on simple classification mistakes.

    john