Re: [media-types] Media subtypes containing "+"

["Murray S. Kucherawy" <[e-mail]>]

Hi Manu, thanks for chiming in.

On Wed, Jul 8, 2020 at 10:15 AM Manu Sporny <[e-mail]>
wrote:

> So, we're getting cornered into having to pick something and it's going
> to come down to:
>
> application/did+jsonld
> application/did+cborld
>
> OR
>
> application/did-ld+json
> application/did-ld+cbor
>
> OR (this seems to be the most tenable one)
>
> application/did+ld+json
> application/did+ld+cborld
>
> The W3C JSON-LD 1.1 WG is at the end of it's life, and has not been able
> to push this decision forward at IETF, so we can't easily register a new
> MIME Type at this point. I'm sure there are some standards shenanigans
> that could be played to do that between W3C Staff and IETF ADs, but
> registering a new MIME Type for "jsonld" is broadly held as the wrong
> thing to do. If we go down that path, IETF might consider rejecting all
> new subtype submissions and JSON-LD will become a cautionary tale of
> where subtypes went wrong... or perhaps there can be guidance given on
> when *not* to use a subtype that would have prevented the JSON-LD folks
> (specifically, me as the Editor at the time) from suggesting
> "application/ld+json" in the first place.
>
> The alternate path is that "application/did+ld+json" is allowed, with a
> clear rationale on why that's a good thing. We have already tested a
> variety of popular MIME Type parsers across multiple languages out there
> in the wild and they seem to do the right thing.
>

> We go into CR in the W3C DID WG in the next couple of months and we'd
> like to register all of the relevant MIME Types for the Decentralized
> Identifier specification by that time. We'd like to register at least
> this one:
>
> application/did+ld+json
>

Mark is asking the right question, I feel: Do we know how well suffixes
have fared, in terms of having been a benefit?  I'm not sure how one would
go about determining this.  I would love to hear suggestions.

What would break on the Internet if we were to do that? Are there other
> options that we're not seeing?
>

I also don't know how to answer this, other than to claim that we tend to
err on the side of being cautious about making assumptions.  Having never
implemented a browser or something else that has to handle media types, I
don't know if I would look for a suffix by searching for a "+" from the
left or from the right, and thus I don't know what would break because the
results here are obviously quite different.

My inclination is to ask that we debate a draft that's an update to RFC
6838, which describes media type suffixes more precisely in a way that
explains how to use what looks like a nested suffix structure like this.
That is, make it clear that "application/did+ld+json" is to be interpreted
as a type of "application" and a subtype of "did" with a suffix of
"+ld+json", or a subtype of "did+ld" with a suffix of "+json", or a subtype
of "did" with two ordered suffixes.

Is someone from the W3C willing to put such a draft together?

-MSK