...Are they also potentially stacked with Arabic vowel signs (harakat)? If so, they interact with them typographically. And the standard specifies that they should therefore have the same combining classes as the harakat. The problem is, the harakat which appear in the same position have different combining classes. And if x<>y, there is no z such that z=x and z=y. So it is impossible to define these new characters in a way which does not conflict with the standard.
Incidentally, the characters U+065A..U+065C are all tonal diacritics for African languages written in the Arabic script. They should not be confused with the similar shaped diacritics which are part of the extended letters of Arabic. The tones can be stacked on Arabic letters which already have letter diacritics as part of their shapes.
Have combining classes actually been defined for these characters?
This is of course exactly the same problem as with Hebrew vowel points and accents, except that this time it applies to real living languages. Perhaps it is time to do something about these combining classes which conflict with the standard.
-- Peter Kirk [EMAIL PROTECTED] (personal) [EMAIL PROTECTED] (work) http://www.qaya.org/
