There has been quite a storm of email on the print by reference subject lately.
Let me once again define what I believe to be a very significant customer
requirement that print by reference can satisfy. In very carefully fencing
this requirement it is important to say what it is not.
It is NOT printing web pages. Much of the concern I have seen expressed in
recent email, especially from HP, has to do with printing web pages. I agree
that chasing links and dealing with the multitude of data types on the web is
very complex and could potentially bloat a Printer implementation.
It is NOT printing documents that require some security mechanism to
access them. In particular it does not deal with the printing of documents
where the right to print a copy of the document must be purchased. As
Larry Masinter has suggested, the protocol may reserve some "space"
to encode credentials for such transactions, but I do not want to complicate
the model nor hold up approval of IPP as a standard trying to architect and
get approval of these security mechanisms.
There are at least two examples of what I think print by reference is for
version one of IPP:
First, consider the case of documents, such as Internet-Drafts, or those
documents which we have on the PWG ftp site which are accessible
by anonymous ftp, i.e. they are "publically accessible". Print by
reference is a powerful tool for printing such documents. Documents
are in some print-ready format, such as Postscript.
Second, consider the case where an enterprise keeps a library of
documents (standards, reports, procedures, etc) on a central
repository that is accessible by anyone within the enterprise
firewall. It would probably be on a private internal network. Print
by reference is again a very powerful tool for printing such
documents which are in some print-ready format.
To summarize, this simple version of print-by-reference only
requires that the documents to be fetched are already
formatted for printing. The Printer does not deal with links,
it does not format pages, it does not deal with dynamic web
formats, etc.
Roger K deBry
Senior Techncial Staff Member
Architecture and Technology
IBM Printing Systems
email: rdebry at us.ibm.com
phone: 1-303-924-4080