[css3-writing-modes] need use case for disabling full-width variants in tatechuyoko runs (was: [CSSWG] Minutes Telecon 2013-08-08)

>From the minutes of the CSS WG call this week:

Topic: 'text-combine-horizontal' and font features (writing modes)
http://lists.w3.org/Archives/Public/www-style/2013Jul/0411.html

> fantasai: You've demonstrated very clearly that there's no reason to use
> 		 full width glyphs in TCY, and argued that we should add an
> 		 implicit text transform from full-width to ASCII
> jdaggett: other properties that affect what digit glyphs are selected
> jdaggett: conflict with TCY where we pick glyphs to combine
> jdaggett: specifying full-width glyphs on a paragraph is strange for
> 		 digits that are gonna be rotated
> fantasai: Author can specify it together with text-orientation:upright
> jdaggett: not a common pattern, shouldn’t add little exceptions for
> 		 poor authoring choices
> fantasai: I don’t think it’s poor choices, might want to do that for
> 		 good reasons.
> fantasai: might prefer to stay within the same font rather than have
> 		 fallback
> dbaron: I think the burden of demonstrating use cases it on the person
> 	   asking for more complexity

I think this last point gets to the heart of this issue, what possible
real-world scenario requires this additional complexity?  I think we need
at least to have a concrete example of an authoring pattern combined with 
actual fonts that requires this.  Without an actual strong reason I think
we should simply omit the "disable full-width variants" requirement.

John Daggett