Re: Defined Private Use was: SSP default ignorable characters

From: Kenneth Whistler (
Date: Wed Apr 28 2004 - 19:33:06 EDT

  • Next message: Dean Snyder: "RE: New contribution"

    > In that case, the text of the standard needs to be amended to remove
    > this ambiguity. But as this amendment would in effect have the
    > consequence of making the PUA useless for any kind of data interchange

    ...which utterly ignored the fact that in the very mail that you are
    responding to, I just conveyed Ewellian characters to you, using
    PUA code points at intended by the standard and common reference to
    a private agreement posted in a publicly available location which
    enables both you and me to interpret those code points.

    > (and what is not data interchange is outside the scope of Unicode), I
    > would strongly oppose any such change. If you want to abolish the PUA,

    I do not, and have no idea why you are imputing that to me, except,
    I suppose, because I have been speaking against your position.

    > have the courage of your convictions and propose doing so (or at least
    > formally deprecating it), instead of leaving it in the standard in a
    > form which makes it look useful but in fact be useless.

    Not only is it useful -- it is in wide *USE*, not only in my own
    company's software, where its use has been *REQUIRED*, and in some
    contexts which were urgent and important, but also, I presume,
    by many other software companies.

    The fact that my company's use of PUA code points does not turn you
    on or solve your problem is, frankly, your problem, not mine. My
    own use is, after all, a *private* use of private-use code points,
    and in this case the people who need to know about them don't require
    me to post a public specification on to share in
    the private agreement.

    > >A group of users with a private agreement *cannot* reasonably
    > >assume that software which supports the PUA in general supports
    > >their particular agreement. They have to investigate what the
    > >capabilities of that software, to see what it might or might
    > >not support in the way of particular behavioral extensions
    > >implied by your private agreement. And in most cases, you
    > >would either have to add on behavior yourself or pay someone
    > >else to do it for you. ...
    > >
    > Which comes back to my billions of dollars. Well, maybe only millions if
    > something can be hacked into an existing OS.

    What you seem to be looking for, Peter, is an *application* that
    supports your particular uses for PUA code points.

    *Applications* don't just fall off of trees. Programmers write
    them, and managers have to come up with budgets to hire programmers
    to write them.

    If you want to go *cheap*, then use of the PUA is easy:


    U+E000 = SNOREFRED LOGO CHARACTER (glyph: an elmtree with two chipmunks)


    "Come shop at Snorefred's (TM) friendly store!"

    Now Snorefred can distribute his own font with the U+E000 character
    designed and mapped accordingly, and away you go. Most everything
    will do the right thing.

    But if Snorefred decides that his logo has to be composed of
    an elm tree with two combining chipmunks and comes in a case pair
    and is bidi-mirrored besides, then I'm afraid he is looking at
    a major programming expense to create web plug-ins and text
    processing add-on's to get his logo to display "right". His
    choices have created a need for applications which don't just
    come off the shelf at CompUSA.


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