[media-types] Macintosh file type code

["Chris Lilley" <[e-mail]>]

It is not clear to me what, in a Media Type registration, the "Macintosh file type code" is for, or what the allowed range of tokens is, or whether anyone checks this information or uses it in any way.

It seems that this code is for use on Mac OS 9 or earlier, i.e. pre-OS X. 

Apple seems to have replaced this with "Uniform Type Identifiers".
https://developer.apple.com/library/content/documentation/FileManagement/Conceptual/understanding_utis/understand_utis_intro/understand_utis_intro.html
and says that there are various legacy sources of it 
- the four character codes (Macintosh file type code)
- filename extensions
- "MIME types" (sic)
and that Uniform Type Identifiers "replaces all these incompatible tagging methods with the string ..."

There seems to be a registry of System-Declared UTIs
https://developer.apple.com/library/content/documentation/Miscellaneous/Reference/UTIRef/Articles/System-DeclaredUniformTypeIdentifiers.html#//apple_ref/doc/uid/TP40009259-SW1


RFC6833, section 4.12 Additional Information has a reference to MacOSFileTypes

[MacOSFileTypes] Apple Computer, Inc., "Mac OS: File Type and Creator Codes, and File Formats", Apple Knowledge Base Article 55381, June 1993, <http://www.info.apple.com/kbnum/n55381 [http://www.info.apple.com/kbnum/n55381]>.

and the link has rotted.

On to my actual questions:

1) Is there continuing value in providing this data in a Meda Type registration, given that it does not seem to be used by current Apple products and has been replaced, as far as Apple is concerned, by UTIs?

I see some registrations say 'none' as the value. It seems better to me to just remove this field from the template.

2) Is there value in adding the Apple UTI (which is at least documented, and in current use) to the registration templates? 

My reason for asking is draft-ietf-justfont-toplevel
https://datatracker.ietf.org/doc/draft-ietf-justfont-toplevel/

which will define a new top-level Media Type for fonts. I am very tempted to just remove the "Macintosh file type code" from the registration template, and could go either way on replacing it with an "Apple Uniform Type Identifier" field - opinions welcome.

Raisng on this list since it affects all other registration templates as well.

--
Chris Lilley
@svgeesus
Technical Director @ W3C
W3C Strategy Team, Core Web Design
W3C Architecture & Technology Team, Core Web & Media