Tables: BackwardCompatible Maintanence

[Martin Duerst]

At 02:58 08/12/11, Erik van der Poel wrote:
>On Wed, Dec 10, 2008 at 9:23 AM, Mark Davis <mark at macchiato.com> wrote:
>> For the X/Y characters, the choices are:
>>
>> BackwardCompatible automatic - stability is the norm, IETF can write RFC if
>> it wants to change to follow Unicode.
>>
>> BackwardCompatible not automatic - instability is the norm, IETF can write
>> RFC if it wants to maintain stability.
>>
>> Either of these two models can work - the first would be safer from a
>> stability point of view.
>
>There is a 3rd model:
>
>BackwardCompatible semi-automatic - implementors are encouraged not to
>implement new versions of Unicode in IDNA until the IETF (or some
>group of experts) has declared the chosen action (i.e. addition to
>BackwardCompatible or addition to Exceptions).

This is EXACTLY what we want to AVOID. The main goal of INDA200x,
in my opinion, is to make additions to Unicode available to IDNs
without a waiting period and unnecessary human involvement.

>> The situation on eszett was not an oversight in IDNA2003. It was discussed
>> at great length. And it is not a clear-cut case. There are a handful of
>> problematic cases:  eszett, final sigma, and the Turkish i's. These were all
>> ugly problems before Unicode; there wasn't much of a way around them. Had
>> the Germans had an uppercase eszett, the Greeks a final capital sigma, and
>> the Turks chosen a different accent on the i rather than have their casing
>> be inconsistent with every other Latin alphabet, it would have been far, far
>> easier for software. But Unicode has to recognize existing usage.
>
>I'm sorry, but this is not very persuasive. There is really nothing
>you can say to convince me that eszett was not botched. Either the
>Unicode case-mappings were recommended too forcefully, or the IETF
>accepted them too easily, or the German registry was not present, or
>the German registry changed their mind in 2008, or some combo of the
>above. Either way, at the end of the day, it's botched.

I was involved then. Basically, the way it went was:
IETF: we need something telling us how to deal with case mapping,
    especially these special cases.
Unicode: we have SpecialCasing.txt
IETF: Okay, we'll take that
Some individuals (including me): But for character foo, is this really
    the right thing to do? The main purpose of SpecialCasing.txt is
    for thing like search; identification may have different needs.
IETF: If we start discussing this in detail, we'll never finish
    the spec. SpecialCasing.txt is the only thing we have, so let's
    go with it.

Regards,    Martin.


#-#-#  Martin J. Du"rst, Assoc. Professor, Aoyama Gakuin University
#-#-#  http://www.sw.it.aoyama.ac.jp       mailto:duerst at it.aoyama.ac.jp