Tamil Numerals in IDNA - Re: WG Last Call for Four Primary IDNABIS I-Ds

[John C Klensin]

(for convenience, I've removed several addressees whom I know to
be following the list)

--On Thursday, August 20, 2009 20:18 -0700 Paul Hoffman
<phoffman at imc.org> wrote:

>>> This is a result of case-by-case analysis of individual
>>> characters.  If one does not want the characters in a label
>>> then do not allow them during registration.
>> 
>> James, without taking a position on this, it is not
>> "case-by-case analysis of individual characters".  It is
>> exclusion of a block, albeit a small one.
> 
> Is it a "block" defined in Unicode? I don't see it, but I
> could be missing something.

No, it is not.  I was using "block" more informally.  The point
I was trying to make is that I see a considerable difference
between, e.g.,

	"exclude Tamil numerals"
	
	and 
	
	"this character looks like that character, so exclude
	one of them". 

The latter is clearly part of a case-by-case character analysis.
The former, whatever it might be, is a decision about a class of
characters, whether Unicode's selection of properties identifies
it as a class or not.

Again, I haven't formed a personal opinion about this request.
I'm just trying to keep the consideration process from getting
muddied by what I believe to be an incorrect claim about the
nature of what is being proposed.   

FWIW, while I understand that circumstances probably could not
have permitted this input to come earlier, I'm very anxious
about making character-exclusion or character-inclusion changes
at this very late date.  We should try to review the change and
make it if appropriate, but haste about these things does not
make good decisions.   In particular, I know that there are
Tamil-speaking and -writing communities in several countries. I
think we have some obligation to be quite confident that the
usage of European digits rather than the historical Tamil digits
in Sri Lanka is also the usage in those other communities.  If
for some reason it were not, then DISALLOWing these digits would
be a very bad idea indeed.

     john