IFX Mail Archive: RE: IFX> RE: Fax processing confirmation;

IFX Mail Archive: RE: IFX> RE: Fax processing confirmation;

RE: IFX> RE: Fax processing confirmation; document-formats

From: ned.freed@mrochek.com
Date: Mon Mar 12 2001 - 12:55:39 EST

  • Next message: Carl Kugler: "RE: IFX> RE: Fax processing confirmation; document-formats"

    > My point is that if the purpose of the attribute exchange is to avoid
    > incompatibilities between sender and receiver, the current design isn't
    > going to work reliably. For example, there is the scenario of a client
    > sending a PS3 file to a PS2 IPP Printer.

    You're making the very big assumption that PostScript breaks down cleanly by
    simple version numbers. But it never has been this way, and hasn't been since
    Level 2 was defined. Devices are free to implement subsets of level 2 or level
    3 and can check the declarations in a document to see if the document uses
    anything outside of the subset they implement. So a simple version number just
    doesn't work very well for PostScript.

    However, the earlier example I saw was PCL. I don't know enough about PCL to
    say whether a simple version number is useful. If it is then defining a MIME
    version parameter for PCL might be appropriate.

    But while simple versioning through the use of MIME parameters is OK, anything
    more than that isn't something MIME parameters were designed to do. Nor are
    MIME content type parameters all that good at negotiating feature sets or
    anything similar.

    We have a mechanism for complex version and feature declaration and
    negotiation: Media feature tags.

    If attribute exchange is your goal you should be using media feature tags. MIME
    content type parameter information is only a small subset of the information
    available in this context. And if you need additional feature tags for
    PostScript or PCL, by all means define them.


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