Re: [css3-fonts] low-level font features

On 22 Jun 2010, at 14:55, Tal Leming wrote:

> 
> On Jun 21, 2010, at 10:48 PM, John Daggett wrote:
> 
>> For OpenType fonts, the example below would be valid syntax but would be
>> effectively ignored since neither of the tags are valid OpenType feature
>> tags:
>> 
>> font-feature-settings: this(5), that(0);
> 
> Regarding "effectively ignored": Would the UA have a list of the registered feature tags and skip anything that isn't in that list or would it accept everything and pass the responsibility for filtering to the text layout engine? The OpenType spec allows the use of unregistered feature tags [1]. If a font has such a feature defined, say LOLZ feature in GSUB, could it be accessed like this?
> 
> 	font-feature-settings: LOLZ;

Emphatically YES. A large part of the point of font-feature-settings is to allow font designers and web authors access to the features they need without waiting for standardizers and browser implementers to catch up with every new feature, registered or not. This will be particularly important in specialized technical or minority-language contexts, where the community needing a feature may struggle to push it through the standardization process in a timely manner.

If we don't allow this, experience suggests that people will instead "repurpose" existing features for semantically incorrect use-cases, just because "they work", like people used to "support" non-Latin scripts by creating fonts that displayed ASCII character codes as non-Latin glyphs. This has the potential to do long-term harm to data integrity and usability, and thereby harm the Web as a whole. It's better to enable people to use things that are explicitly not standardized -- like the Unicode PUA -- where necessary than to push them towards the ABuse of what is supposed to be standard.

JK

Received on Tuesday, 22 June 2010 14:37:28 UTC