Re: [media-types] Templates for basic MIME types

[Eric Prud'hommeaux <[e-mail]>]

On Fri, Dec 25, 2020 at 11:24:13PM -0800, Ned Freed wrote:
> > My understanding has always been that the registration template is a
> > transient artefact, and is not required to be published. Why is there a need
> > for this?
> 
> Quite right - there is no need for this activity.
> 
> Registration templates are a handy tool for collecting and submtting the 
> information necessary for a registration, nothing more.

AFAICT, de facto media types include only the tree and the subtype
name, and references to specs ¹. Some of these specs may define some
parameters but the information isn't organized in a familiar way,
which means you have to dig way harder to find established consensus.

For instance, the two example media types, image/{jpeg,gif} are sort
of registered in RFC2046 but you can't look there to see if e.g.
image/jpeg can take an encoding parameter to switch between JFIF and
EXIF (after some annoying heuristics, it appears that it can't so
folks write EXIF + JFIF into JPEGs).

I read the proposal as offering to clarify that and all of the other
marvelous metadata (security, encoding, interop consideration and
fragment IDs) that has accumulated in the registration template over
the years ².

¹ https://www.iana.org/assignments/media-types/media-types.xhtml#image 
² https://www.iana.org/form/media-types


> The actual publication requirements for media types are laid out in section
> 4.10 of RFC 6848. Templates aren't mentioned in that section.
> 
> Sometimes templates end up getting published - the IETF does it routinely. Some
> other standards bodies do so as well, others do not.
> 
> It's also the case that more information required to register now than
> in the past. But increased information requirements do not apply retroactively
> to previously registered media types. (It should be obvious why this is the
> case.)

True, we can't change the deployment, but it still may be worth
documenting it.


> Of course nothing precludes engaging in this activity. But like Mark, I don't
> see any actual need. And if you really want to spend time on media types, there
> are plenty of entirely missing types that would benefit from being registered.

I can imagine you are speaking either of

1 formats for which there is a specification (e.g. W3C XML Schema) and
  no corresponding media type (i.e. I have to inspect an
  application/xml document to know if it's XML Schema)

2 commonly-used media types that don't show up in the registry (no
  examples come to mind)


> 				Ned
> 
> > > On 26 Dec 2020, at 3:17 am, Eric Prud'hommeaux <[e-mail]> wrote:
> > >
> > > And I'll ask for sweeping changes that invalidate the billions of existing deployments...
> > >
> > > Happy holidays, all!
> > >
> > >
> > > On Thu, Dec 24, 2020 at 02:48:09AM +0200, Chris Lilley wrote:
> > >> I'm happy to review any of the image media types.
> > >>
> > >> On 2020-12-24 00:37, Murray S. Kucherawy wrote:
> > >>> There are a number of media types registered by RFCs 2045 and 2046
> > >>> implicitly (e.g., image/jpeg, image/gif).  The media type registry has
> > >>> entries for them pointing at those two documents, but the documents
> > >>> never actually present registration templates for any of them.
> > >>>
> > >>> Just to make the record complete, I plan to send the reviewers a set of
> > >>> registration templates for them.  I'll post them here as well in case
> > >>> anyone wants to comment.
> > >>>
> > >>> I presume we're fine with that approach, rather than requiring an RFC?
> > >>>
> > >>> -MSK, ART AD
> > >>>
> > >>> _______________________________________________
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> > >>> [e-mail]
> > >>> https://www.ietf.org/mailman/listinfo/media-types
> > >>
> > >> --
> > >> Chris Lilley
> > >> @svgeesus
> > >> Technical Director @ W3C
> > >> W3C Strategy Team, Core Web Design
> > >> W3C Architecture & Technology Team, Core Web & Media
> > >
> > >> _______________________________________________
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> > >> https://www.ietf.org/mailman/listinfo/media-types
> > >
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> 
> > --
> > Mark Nottingham   https://www.mnot.net/
> 
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