[IPP] NODRIVER: Seeking consensus on a solution for use cases 3.2.20 and 3.2.21

Greetings,

In the last review of IPP Driverless Printing Extensions v2.0, concerns were once again raised about extending the set of enum values for "print-quality" to solve the "Manufacturer-Deployed Print Quality Mode" and "Administrator-Deployed Print Quality Mode" use cases (3.2.20 and 3.2.21 in the 20200204 published draft <https://ftp.pwg.org/pub/pwg/ipp/wd/wd-ippjobprinterext3v20-20200204.pdf>). I want to see if we can hash this out via email in between meetings.

Before we dive into the implementation choices, I want to focus on the use cases and the user experience(s) we want to support. The use cases I have articulated are important to HP, and I have to believe that they are also important to other printer vendors.

The "print-quality" attribute as defined originally in IPP/1.0 (RFC 2566) has remained unchanged for over 20 years:

4.2.13 <https://tools.ietf.org/html/rfc2566#section-4.2.13> print-quality (type2 enum)

   This attribute specifies the print quality that the Printer uses for
   the Job.

   The standard enum values are:

     Value  Symbolic Name and Description

     '3'    'draft': lowest quality available on the printer
     '4'    'normal': normal or intermediate quality on the printer
     '5'    'high': highest quality available on the printer

Since semantically there is a linear progression from "draft" to "normal" to "high", a "Print Quality" UI selection control could be presented as a slider, or more generically as a radio button group or a pop-up or table list, where only one option can be chosen. The ordering of the three choices is clear and common sense dictates that they should be presented in order rather than out-of-order.

Unfortunately, though, this long-standing definition doesn't provide for the possibility that the Printer supports more than 3 quality levels. Nor does it provide space for vendor-defined or site-defined levels, which have existed for quite some time, but always been described in terms of vendor-unique attributes or via legacy (non-IPP) mechanisms. I strongly believe that we need to find a way to allow printers to express their additional print quality options in a way that allows simpler UIs to maintain their simplicity but still allows access to these printer-provided non-standard print quality levels.

So, my questions are these:

1. Are there any specific objections to these use cases? I believe these are important to all printer manufacturers, not just HP, as a way of expressing an important vector of product differentiation without having to adopt vendor-unique or site-unique attributes, which many universal clients ignore. This undermines efforts to move away from model-specific drivers.

2. Assuming agreement with the use cases, if we had a green field / blank sheet of paper, how to support the use cases in IPP?

Option 1: Extend "print-quality" as per the current proposal

Option 2: "print-quality-percent" as per Mike's proposal, which I don't think adequately addresses the use cases

Option 3: Define a new "print-quality-col", which could contain a "print-quality-percent" but could also have printer-provided localized labels and tooltips.

Option 4: ???

Please share your thoughts and feedback!

Smith

/**
    Smith Kennedy
    HP Inc.
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[IPP] NODRIVER: Seeking consensus on a solution for use cases 3.2.20 and 3.2.21

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