Re: [Justfont] Internet Media type for font collections

I am not sure if there is a use case where specifying the fact that a font file is the font collection is important but if there is - we can define another subtype for font collections and use the same optional parameters to specify what types of outlines / layout mechanism are supported.

Thanks,
Vlad

-----Original Message-----
From: Justfont [mailto:justfont-bounces@ietf.org] On Behalf Of Chris Lilley
Sent: Saturday, February 06, 2016 9:22 AM
To: justfont@ietf.org
Subject: [Justfont] Internet Media type for font collections

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

_______________________________________________
Justfont mailing list
Justfont@ietf.org
https://www.ietf.org/mailman/listinfo/justfont