Subject: IPP> Re: MIME types

From: Tom Hastings <[email-masked]>
Date: Fri, 12 Sep 1997 11:27:57 PDT

Larry,

Thanks for the help on MIME-type mapping. I've taken on an action item
to make a strawman proposal for next week's IPP meeting.

So could the PWG forward a whole bunch of registration proposals of the
form:

  'application/vnd.xxx-yyy

where xxx is the company and yyy is the name of the PDL using the current
IANA printer-language registration list (from the Printer MIB)

except for the ones that are already registered (Postscript, PDF, and PCL)?

A few questions about PDLs, that aren't from a particular vendor:

for langSimpleText, you recommended: "text/plain"

and Harald has recommended "application/octet-stream" for the
automatic sensing, though he also indicated we could make up a
more specific one.  If we did want to make up a more specific one,
since IPP is on standard track, wouldn't it be something like:

  "application/auto-sense"

and we would have to supply a specification for reference in the
IANA registration.  Could we just reference a separate appendix of the 
IPP Model document for the meaning of "application/auto-sense"?

Thanks for your help.

Tom

At 22:21 09/10/97 PDT, Larry Masinter wrote:
>> We also agreed that those Printer enums that already have registered
>> MIME-types:  'application/postscript', 'application/pdf', and vnd.hp-PCL
>> should use those MIME-types.
>> 
>> ISSUE: Should the PWG register the rest as 'application/xxx' because IPP is
>> on standards track or should the PWG register the rest as 'vnd.vv-xx'?
>> 'application/xxx' requires a document specifying the semantics of each
>> MIME-type.
>> 
>
>Uh, MIME types have two parts: a top level and a subtype. The top level
>for most printer documents is "application", unless you can argue that
>it fits under "image". (I believe that pdf could arguably be represented
>as 'image' rather than 'application', but they chose application/pdf.)
>
>Under the new rules, you either get an unadorned name ("postscript") or
>an adorned one ("vnd") based on whether the type is standards track.
>Postscript and PDF are grandfathered in, since they were named before
>the
>rule was made; if they were being reregistered today they'd be known
>as application/vnd.adobe-ps and application/vnd.adobe-pdf, I believe.
>
>I think that almost all printer formats that are not already registered
>would most likely go into the "vnd." hierarchy since they're not
>standards
>track.
>
>Larry
>-- 
>http://www.parc.xerox.com/masinter
>
>

---

From: Jay Martin <[email-masked]>
Date: Fri, 12 Sep 1997 15:16:59 -0400

As I understand it (and Larry would know best), the standard MIME
type of "application/octet-stream" is the universal equivalent of
"go fish" in the web/email worlds.

I think IPP should follow this de facto standard and NOT devise
a new MIME type (such as "application/auto-sense"), as no real
value appears to be added by this approach. 

	...jay

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---

From: Larry Masinter <[email-masked]>
Date: Sun, 14 Sep 1997 11:52:55 PDT

Tom,

I am not the authority on the IETF MIME registration proceedure,
I've just observed it in practice and have read the relevant RFCs.
I don't imply that these answers are authoritative.

I believe that the registrant for a "vnd.xxx-" designation
should logically be the owner of the "xxx-" trademark, and that
trying to register data types in the name of someone else is
a bad idea.

The type "application/auto-sense" doesn't make sense to me.
MIME types designate the type of enclosed content. If you don't
know the type, you can supply "application/octet-stream", if
you, for example, know absolutely nothing about the data type.
However, "application/unknown-print-file" might be a type for
designating "this is a file intended for shipping to an autosense
printer, but it isn't just some arbitrary bucket of bits."

As for whether you can reference a separate appendix of the
IPP model document, I think the requirements for having a public
specification are fairly generic.

Larry