Feedback on the proposal to change U+FFFD generation when decoding ill-formed UTF-8

Martin J. Dürst via Unicode unicode at
Tue May 23 03:24:31 CDT 2017

Hello Mark,

On 2017/05/22 01:37, Mark Davis ☕️ via Unicode wrote:
> I actually didn't see any of this discussion until today.

Many thanks for chiming in.

> (
> unicode at mail was going into my spam folder...) I started
> reading the thread, but it looks like a lot of it is OT,

As is quite usual on mailing list :-(.

> so just scanned
> some of them.
> A few brief points:
>    1. There is plenty of time for public comment, since it was
> targeted at *Unicode
>    11*, the release for about a year from now, *not* *Unicode 10*, due this
>    year.
>    2. When the UTC "approves a change", that change is subject to comment,
>    and the UTC can always reverse or modify its approval up until the meeting
>    before release date. *So there are ca. 9 months in which to comment.*

This is good to hear. What's the best way to submit such comments?

>    3. The modified text is a set of guidelines, not requirements. So no
>    conformance clause is being changed.
>    - If people really believed that the guidelines in that section should
>       have been conformance clauses, they should have proposed that at
> some point.

I may have missed something, but I think nobody actually proposed to 
change the recommendations into requirements. I think everybody 
understands that there are several ways to do things, and situations 
where one or the other is preferred. The only advantage of changing the 
current recommendations to requirements would be to make it more 
difficult for them to be changed.

I think the situation at hand is somewhat special: Recommendations are 
okay. But there's a strong wish from downstream communities such asWeb 
browser implementers and programming language/library implementers to 
not change these recommendations. Some of these communities have 
stricter requirement for alignment, and some have followed longstanding 
recommendations in the absence of specific arguments for something 

Regards,   Martin.

>       - And still can proposal that — as I said, there is plenty of time.
> Mark
> On Wed, May 17, 2017 at 10:41 PM, Doug Ewell via Unicode <
> unicode at> wrote:
>> Henri Sivonen wrote:
>>> I find it shocking that the Unicode Consortium would change a
>>> widely-implemented part of the standard (regardless of whether Unicode
>>> itself officially designates it as a requirement or suggestion) on
>>> such flimsy grounds.
>>> I'd like to register my feedback that I believe changing the best
>>> practices is wrong.
>> Perhaps surprisingly, it's already too late. UTC approved this change
>> the day after the proposal was written.
>> --
>> Doug Ewell | Thornton, CO, US |

Prof. Martin J. Dürst
Department of Intelligent Information Technology
College of Science and Engineering
Aoyama Gakuin University
Fuchinobe 5-1-10, Chuo-ku, Sagamihara
252-5258 Japan

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