IPP> Document-format attribute.. [ipp-mod] clarification

IPP> Document-format attribute.. [ipp-mod] clarification

IPP> Document-format attribute.. [ipp-mod] clarification

McDonald, Ira imcdonald at sharplabs.com
Mon Apr 3 19:10:15 EDT 2000

Hi Tom and Michael,

Right.  All 'sniffer' algorithms have known bugs and limitations.
We shouldn't be encouraging client implementors (or end users)
to punt and just specify 'application/octet-stream' when they
know better.

I also agree with Tom that we should get moving on registering
the PDLs in common use in the printer industry that are not 
currently MIME registered.  Volunteers to do this work?

- Ira McDonald, consulting architect at Xerox and Sharp
  High North Inc

-----Original Message-----
From: Hastings, Tom N [mailto:hastings at cp10.es.xerox.com]
Sent: Monday, April 03, 2000 3:59 PM
To: Michael Sweet; McDonald, Ira
Cc: 'harryl at us.ibm.com'; anthony.porter at computer.org; ipp at pwg.org;
venky at teil.soft.net
Subject: RE: IPP> Document-format attribute.. [ipp-mod] clarification

We've talked a lot about registering all of the PDLs that are in the Printer
MIB that don't already have a MIME type.  Maybe we need to push that
approach.  The problem with a client specifying 'application/octet-stream'
when it knows better, is that the Printer may have trouble distinguishing
between some of its supported formats.


-----Original Message-----
From: Michael Sweet [mailto:mike at easysw.com]
Sent: Thursday, March 30, 2000 08:07
To: McDonald, Ira
Cc: 'harryl at us.ibm.com'; Hastings, Tom N; anthony.porter at computer.org;
ipp at pwg.org; venky at teil.soft.net
Subject: Re: IPP> Document-format attribute.. [ipp-mod] clarification

"McDonald, Ira" wrote:
> Hi folks,
> I agree with Harry that we should further revise this paragraph
> to indicate that a client MUST specify a particular document
> format when known and MUST NOT use 'application/octet-stream'
> instead.

Um, that probably won't work too well, since many printer-specific
data streams do not have registered MIME types (e.g. Canon, ALPS,
EPSON, Lexmark, etc.), and a generic print server (e.g. JetDirect,
Axis print server, etc.) probably won't know enough to be able to
enumerate the supported MIME types for the actual device.

SHOULD and SHOULD NOT are probably more appropriate if we are
trying to "encourage" rather than "enforce".

Also, the application/octet-stream information should probably be
updated to reflect a special case for printer objects that list
only application/octet-stream for document-format-supported.
That is, if a client knows the MIME type but the printer object
only supports application/octet-stream, then the printer object
is just acting as a "dumb" printer buffer and the client must
only use the default document format or pass

Michael Sweet, Easy Software Products                  mike at easysw.com
Printing Software for UNIX                       http://www.easysw.com

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