Subject: IPP> MOD - ISSUE: SHOULD vs SHALL on document-format supplied by client?

From: Tom Hastings <[email-masked]>
Date: Fri, 26 Sep 1997 17:20:18 PDT

I have an issue with only making the "document-format" attribute
a SHOULD when supplied by the client.  It seems to me that if the
client supplies a "document-format" value, the Printer MUST honor it
or reject the job.

In fact, the "document-format" attribute shouldn't be affected by the
value of the "ipp-attribute-fidelity" attribute.  The Printer MUST reject
the job if it gets a "document-format" value supplied by the client that
the Printer doesn't support.  In ISO DPA, the "document-format" attribute
did NOT have the compulsory/non-compulsory property (the equivalent of IPP's
"ipp-attribute-fidelite" Job attribute.

So should the SHOULDs be changed to SHALLs below?

And should we specify that "ipp-attribute-fidelity" doesn't affect
"document-format"?

Tom

One special type is 'application/octet-stream'.   If the Printer object
supports this value, the Printer SHALL be capable of auto-sensing the format
of the document data. If the Printer object's default value attribute is set
to 'application/octet-stream' the Printer object not only supports
auto-sensing of the document format, but will depend on the result of
applying its auto-sensing algorithm in the case of missing information not
supplied by the client.  If the client supplies a document format value, the
Printer SHOULD rely on the supplied attribute, rather than trust its
auto-sensing algorithm.  To summarize:

1. If the client does not supply a document format value, the Printer must
rely on its default value setting (which may be 'application/octet-stream'
indicating an auto-sensing mechanism).

2. If the client supplies a value other than 'application/octet-stream', the
client is supplying valid information about the format of the document data
and the Printer object SHOULD trust the client supplied value more than the
outcome of applying an automatic format detection mechanism.  For example,
the client may be requesting the printing of a PostScript file as an
'text/plain' document.  The Printer object SHOULD print a text
representation of the PostScript commands rather than interpret the stream
of PostScript commands and print the result.

3. If the client supplies a value of 'application/octet-stream', the client
is indicating that the Printer object SHOULD use its auto-sensing mechanism