Script tags not listed in any shaping engine documentation

[NorbertLindenberg]

The "Script Tags" register includes a number of script tags which are not listed in any shaping engine documentation. Here's an initial subset of them: 'hluw', 'avst', 'bamu', 'bass', 'bopo', 'brai', 'byzm', 'cans', 'cari', 'aghb', 'cher', 'hani', 'copt', 'cprt', DFLT, 'dsrt', 'elba', 'ethi', 'glag'.

As far as I know, every script has to be supported by some shaping engine – the documentation should make clear which one. Now that there are two different shaping engines that handle large numbers of scripts, there's no clear default anymore.

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Document Details

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• ID: 194a6d3c-4137-46e9-3a4b-44b990200986
• Version Independent ID: a0c8e788-5228-aa28-670e-3ba1ac3faecd
• Content: Creating and supporting OpenType fonts for the Universal Shaping Engine - Typography
• Content Source: typographydocs/script-development/use.md
• Product: typography

[PeterCon]

This doesn't appear to be feedback on the OpenType spec, per se, but rather about other specs on shaping engine implementations. Since there's no change in the OT spec required, I'm closing this issue. If you think it's needed, you can open a separate issue on some other content in the Typography site.

[NorbertLindenberg]

So where do you suggest I file this bug? And where should it be fixed? It’s clear that there is a bug. Implementers of OpenType rendering systems, tool developers, and font developers all need to know which shaping engine handles which script. And the only reasonable way to manage this is by having a single document that maps script tags to shaping engines.

[NorbertLindenberg]

Please reopen this bug.

[PeterCon]

The only potential action that could be taken on this page to make sure there aren't script tags listed here that aren't covered in some shaping engine spec would be to remove tags from this page. Obviously that's not the right answer.

I suggest you open an issue on this page: that will put the issue into the right set of content within the Typography site.

[NorbertLindenberg]

I don’t think the USE page is any more appropriate than this page, and it’s still within the same repository and therefore the same set of issues anyway. Please leave this bug open until we’ve figured out what the right fix is.

[PeterCon]

USE is more appropriate because it's in a section of the site and repo for script implementation specs. This page is part of the OpenType font format spec, which is different. There would not be any changes to the OT spec for this.

Re-opening, but changing page links.