The problem I see here is that ZWJ is not intended to create ligatures between diacritics, only between clusters that would otherwise still be a single combining sequence. Normally CGJ would have fitted better there, but this conflicts with the intent to address the canonical combining order with CGJ.
It also conflicts with the expectation that CGJ will *not* affect rendering. ZWJ is intended to affect rendering, which is why it makes more sense than CGJ, but I agree that, as currently defined, it does not seem to be intended to create ligatures between combining marks. However, I recall Paul Nelson at MS stating that they also needed ZWJ to work between combining marks for another script (Khmer perhaps?). This suggests to me that either the definition of ZWJ and ZWNJ needs to be revised, or a new ZERO-WIDTH COMBINING MARK JOINER needs to be encoded.
While we're about it, we could propose a spacing, non-breaking ELIDED CHARACTER for use in ketiv/qere where combining marks need to be applied to empty space within a word.
John Hudson
Tiro Typeworks www.tiro.com Vancouver, BC [EMAIL PROTECTED]
I sometimes think that good readers are as singular,
and as awesome, as great authors themselves.
- JL Borges
