Re: Unicode Stability

From: Doug Ewell (
Date: Thu Mar 03 2005 - 02:16:00 CST

  • Next message: Asmus Freytag: "Re: Unicode Stability"

    Peter Kirk <peterkirk at qaya dot org> wrote:

    > ... But I find it hard to reconcile with the whole concept of a
    > standard which is supposed to specify how text should be represented,
    > as well as with Doug Ewell's definition of stability that "it does not
    > change in a way that causes existing implementations or data to
    > break".

    to which Asmus Freytag <asmusf at ix dot netcom dot com> responded:

    > As stated, that definition is clearly nonsense.

    Okay, hold on a minute. I'm being quoted out of context. My original
    statement was:

    "'Stability' in a standard does not mean that the standard never
    changes. It means that, as much as possible, it does not change in a
    way that causes existing implementations or data to break."

    Since I wrote that on Tuesday, Peter Kirk has quoted it at least twice,
    but *only the last part* -- not the part where I qualified it with "as
    much as possible," and not the all-important part where this type of
    practical stability is contrasted with absolute immutability.

    My intent in writing this brief description of "stability" -- it is not
    intended as a "definition" -- was to respond to Doug Ulist's question
    about whether the need to check the latest version of the Unicode
    Standard was "in keeping with the idea of Unicode being inalterable."

    I believe the broad response I pulled out of my back pocket was
    consistent with the notion of stability as applied to the Unicode
    Standard, and is not "clearly nonsense." (I'm not sure if Asmus was
    referring to my statement or the context in which Peter quoted it.)
    Stability is not Boolean, and not absolute. It is not the case that a
    standard is either stable and thus never changes, or changes and is thus

    "Unicode" -- here I am deliberately being vague between the standard and
    the standardizing body -- sometimes finds itself in a position where
    absolute stability has to be weighed against the benefit of making a
    change. One example of this is the normalization corrections. At some
    point it is considered better to correct an error in the normalization
    data than to allow the error to remain for the sake of stability. That
    does not mean the UTC is not interested in stability, but that sometimes
    there are other issues weighing against it and a hard decision has to be

    On top of all this, we have a situation where people do not even agree
    on what it means for existing implementations or data to "break."

    Please don't take my back-pocket interpretation of "stability" and carve
    it in stone. I don't speak for the Consortium, and certainly not for
    the UTC (to which I don't belong). My idea of "stability" is mine

    -Doug Ewell
     Fullerton, California

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