Contextual rules

[fujiwara at jprs.co.jp]

> From: John C Klensin <klensin at jck.com>
> > Protocol-05 section 4.3.2.3 "Contextual Rules" are too
> > complicated to implement.
> 
> Could you recommend an alternative?   Otherwise, would you
> prefer to see any characters that require contextual treatment
> simply excluded?  Or do you feel that, e.g., non-spacing breaks
> would not cause problems with Japanese?

I see. I read discussions about ZWNJ and ZWJ characters.

"Contextual Rules" are necessary to support ZWNJ and ZWJ characters.

Any IDNA200X compliant software have complete UNICODE character database,
then implementing "Contextual Rules" check is easy.

-- 
Kazunori Fujiwara, JPRS <fujiwara at jprs.co.jp>