Allowed characters (was: Re: Casefolding Sigma (was: Re: IDNAbis Preprocessing Draft)

[Patrik Fältström]

On 30 mar 2008, at 14.05, Michael Everson wrote:

> The group here wants to understand why is 0675 disallowed while 0622  
> is not. Can you give us an explicit answer?

Because 0675 is not stable under NFKC/casefolding, while 0622 is  
stable. I.e. 0622 matches category A, while 0675 matches categories A  
and B.

    Patrik