The UTC just approved a clarification of the base character definition, as follows:
...
Thank you, Mark. This clarification is useful.
So I conclude that ZWJ and ZWNJ, General Category Cf, are not graphic characters and so neither base characters nor combining characters. Therefore, according to definition D17 (in TUS 4.0 section 3.6, I assume this has not been amended), these characters cannot form part of a combining character sequence. Therefore they cannot be appropriate for forming ligatures between combining characters within such a sequence. Is that correct?
CGJ, however, has General Category Mn, and so is a combining character and can form part of a combining character sequence. But, according to section 15.2, "inserting a combining grapheme joiner between two characters should have no effect on their ligation or cursive joining behavior."
So, is there any other mechanism for requesting ligation of combining characters within the same combining character sequence? If not, there is a need to propose such a mechanism, for Hebrew. I will post details to the Hebrew list.
-- Peter Kirk [EMAIL PROTECTED] (personal) [EMAIL PROTECTED] (work) http://www.qaya.org/
