RE: [css-fonts] font-language-override

On Wednesday, June 01, 2016 5:40 AM Andrew Cunningham wrote:

On Wednesday, 1 June 2016, Levantovsky, Vladimir <Vlaimir.Levantovsky@mvaroousonotype.com<mailto:Vlaimir.Levantovsky@mvaroousonotype.com>> wrote:
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> OpenType maintains its own language tag system where the mappings in most cases are 1:1 and in some cases are n:1, but I wouldn’t consider it a complex mapping – as far as user is concerned, there is always a straightforward mapping from a content language tag to the OT language tag. Changing the content language tag, e.g. by defining a span with a different tag, should do the trick.
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The mappings are 1-1, many-1, 1-many

Can you please provide an example of 1-many mapping for OT language tag?

In at least one case the many-1 mapping contains languages that have incompatible typographic systems. So even if you use the right tag you would need to override aspects of font rendering, which cannot be done in css.

If this is the case, then it should probably be fixed in the spec itself, not via the font-language-override hack.

Also technically the OT tag isn't a language tag in the sense that a BCP language tag is. And the OT tag doesn't specifically identify a language.

Yes, the OT language tags define typographic conventions, and some unrelated languages may share the same set of typographic conventions.

If I had mixed Latin script and Banum script in Bamum language and using  fonts I would be wanting to use diffeent OT language systems for each font for the same language.

Maybe an example be helpful to clarify things – I must admit that based on what I read as part of the description for font-language-override property it isn’t clear how one would accomplish this (and this might be a contributing factor for the feature to be at risk).

Thank you,
Vlad