Re:Canonical ordering

From: Timothy Partridge (
Date: Sat Apr 29 2000 - 20:38:59 EDT

Peter Constable asked

> On page 50 of U3, last paragraph, I read the following:

> "Some specific nonspacing marks override the default
> stacking behaviour by being positioned side-by-side rather
> than stacking or by ligaturing with an adjacent nonspacing
> mark."

> How do I tell which this applies to?

Sometimes the Unicode script description mentions it, other
times knowledge of the writing system is needed.
Greek and Hebrew immediately spring to mind.

> If, suppose, there were some writing system in which
> diacricits like acute and circumflex (say) occured, but the
> could co-occur over the same base character and in that
> situation were expected to be positioned side-by-side, what
> would it take to handle that?

Vietnamese uses the Latin script but doesn't behave as normal.
See for example U+1EA7. Language tagging might be the best
way around the problem. (Special forms of the accent seem to
be frowned upon - see the deprecated U+0341.)


This archive was generated by hypermail 2.1.2 : Tue Jul 10 2001 - 17:21:02 EDT