Nobody particularly wants to perpetuate mistakes. But for any breaking change, we have to be aware of both the benefits <i>and</i> the costs.<div><br></div><div>For example, in an area you're familiar with, one can argue that the placement of the Greek and Hiragana blocks (and a few others) in Unicode is sub-optimal, because they are not aligned on 128-unit boundaries; that affects certain kinds of compression and table lookup. Even though arguably it was a mistake, the value of fixing it would not outweigh the <i>incredibly</i> high cost of fixing it. There are hundreds of like cases in Unicode alone, where <b>if</b> we could do it all over again -- knowing what we know now -- we would have done things differently, but we simply cannot change now.</div>
<div><br></div><div>That's why for protocols such as Unicode -- or domain names -- where there are massive amounts of data and huge numbers of programs using the existing protocol, and where there is a long transition period before everything could possibly switch over, we have to assess any breaking change extremely carefully so that we are absolutely certain that the value outweighs the cost. If, on the other hand, we can come up with an effective transition plan for these 4 characters (and I'm hoping we can), then it would be feasible to change.<div>
<br><div>Mark<br>
<br><br><div class="gmail_quote">On Thu, Dec 3, 2009 at 08:44, Michael Everson <span dir="ltr"><<a href="mailto:everson@evertype.com" target="_blank">everson@evertype.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div>On 3 Dec 2009, at 10:37, Debbie Garside wrote:<br>
<br>
> My philosophy is always to go with backward compatibility if at all<br>
> possible.<br>
<br>
</div>My philosophy is that if a mistake was made in the past it should not<br>
be perpetuated.<br>
<div><div></div><div><br>
Michael Everson * <a href="http://www.evertype.com/" target="_blank">http://www.evertype.com/</a><br>
<br>
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