Re: [Justfont] Internet Media type for font collections

[Ken Lunde <[e-mail]>]

Chris,

I am not sure how helpful this information is, or how it would factor into this issue, but all of the OpenType/CFF Collections of which I am aware use the ".ttc" filename extension, not the ".otc" one. These include the Source Han Sans, Source Han Code JP, and Noto Sans CJK families, along with the large number of OpenType/CFF Collections that are bundled with OS X Version 10.11. The main reason is due to the latter filename extension not being recognized.

It is somewhat unfortunate that two different filename extensions have been deployed for non-collections, meaning ".ttf" and ".otf," and the current situation with collections provides an opportunity to use a single filename extension, specifically the ".ttc" one.

I will add the above to Issue #7.

Best...

-- Ken

> On Feb 6, 2016, at 6:21 AM, Chris Lilley <[e-mail]> wrote:
> 
> Hello,
> 
> It is unclear in the current spec what Internet media Type to use for
> Collections (previously, TrueType Collections but now expanded to
> OpenType as well). I can see several possibilities, which have
> different impacts on the spec.
> 
> a) Just use font/truetype for TTC.
> + avoids adding another type
> - no way to indicate support for collections in an Accept header
> - complicates specifying a fragment identifier (only sometimes legal)
> 
> consequences:
>  need to add .ttc to the file types section
>  change fragment identifiers to allow an optional fragment (but only
>  if ttc)
> 
> Similarly, just use font/opentype for OTC (is .otc the usual filetype?)
> (same pluses, minuses and consequences as for TTC)
> 
> b) Same as a) but add a parameter like collection="true" or something.
> I don't like this option, partly because params are often awkward to
> configure on servers and tend to be little used (or hard coded to
> particular filetypes) and also because it has all the disadvantages of
> a) regarding optional fragments.
> 
> c) Define two new media types, for TTC (TrueType outlines, no OpenType
> layout) and for OTC (CFF or TTF outlines, OpenType Layout)
> - two more types (but at least, no parameters)
> + easy to map to existing filetypes .ttc .otc
> + fragment identifier easy to specify (numeric, the n'th font in the
> collection where n starts at one. If omitted, same as #1)
> + Easy to use in an Accept header
> 
> Option c) is my preferred option, would be interested to hear what
> others think.
> 
> This refers to github issues:
>   Media type for OpenType collections #6
>   https://github.com/svgeesus/ietf-justfont/issues/6
> 
>    Fragment syntax for collections #7
>    https://github.com/svgeesus/ietf-justfont/issues/7
> 
> although the main question for #7 is what media type to put the
> fragment syntax onto. The actual syntax of #1, #2 is uncontroversial
> and already used (but as a non-normative example) in CSS3 Fonts.
> 
> -- 
> Best regards,
> Chris  Lilley
> Technical Director, W3C Interaction Domain
> 
>