Casefolding Sigma (was: Re: IDNAbis Preprocessing Draft)

Michael Everson everson at
Tue Jan 22 20:01:54 CET 2008

At 13:42 -0500 2008-01-22, John C Klensin wrote:

>By contrast, final form sigma is not about character confusion
>in any way.  It is about:
>	(i) Whether final form characters are fundamentally
>	different characters than the base forms of the same
>	characters?

Capital B and small b are different characters. Capital Sigma, small 
sigma, and small final sigma are different characters.

>	(ii) Whether it is necessary and desirable to encode
>	typographic variations in the DNS for IDNs.   Note that
>	a "yes" answer to this question puts one on a slippery
>	slope toward needing to encode glyphs and fonts, rather
>	than characters.

Small final sigma is not a "typographic" variation of small sigma. 
They are not freely interchangeable. So your question is not 
appropriate, it seems to me.

>	(iii) What the general rules should be for presentation
>	variations of characters that are normally
>	position-sensitive and whether Greek final sigma is a
>	sufficiently special case that it should be treated
>	differently from all other final forms or
>	context-sensitive presentation forms more generally.

The idea that Greek users should not be allowed to use final sigma is 
shocking to me. There must be a technical solution found for them.
Michael Everson *

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