Tables and contextual rule for Katakana middle dot

Vint Cerf vint at
Wed Apr 8 00:53:18 CEST 2009

two cents:

I would imagine, perhaps naively, that punctuation ought generally to  
be disallowed and that exceptions should be handled as exceptions for  
what I hope would be compelling reasons.


Vint Cerf
1818 Library Street, Suite 400
Reston, VA 20190
vint at

On Apr 7, 2009, at 6:50 PM, Eric Brunner-Williams wrote:

> Mark Davis wrote:
>> ...
>> There are other dot-like characters that are far more visually  
>> similar
>> to dot, like Arabic zero.
>> عربي٠عربي.com <>
>> vs
>> عربي.عربي.com <>
>> But more importantly, there is a real lack of data presented for  
>> these
>> kinds of positions. When excluding characters that are in common use
>> on the basis of visual confusability, such as Katakana middle dot,
>> let's see some real data on what a difference this would make in
>> overall visual confusability of characters. Of all of the visually
>> confusable characters in PVALID, what would be the percentage
>> difference but adding or removing Katakana middle dot? And why do
>> people think this can't be handled by exactly the same mechanisms  
>> that
>> programs have to handle the visually confusable characters that *are*
> I applied the no-punctuation principle when looking at U+166E.  
> However,
> it (a very small baseline aligned "x") really doesn't look like a  
> label
> separator, and there really is no harm in a Cree full stop appearing
> within a Cree character string, creating labels of the form
> "whatever<dot>cree-sentence-1<mini-x>cree-sentence-2<dot>else.
> So, I have some second thoughts about DISALLOWED for  U+166E. The case
> for PVALID is ... well ... inventive, not compelling.
> For U+166D, a symbol, I'm willing to keep it DISALLOWED, for several
> reasons.
> I wrote this because I think you're correctly asking what's really
> confusable, and the question is larger than just Katakana middle dot.
> Eric
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