Re: What's the BMP being saved for?

From: Doug Ewell (
Date: Fri Mar 19 2004 - 11:25:56 EST

  • Next message: Jon Hanna: "Re: Irish dotless I"

    Marion Gunn <mgunn at egt dot ie> wrote:

    > BMP is part of 10646-speak, and probably part of pre-Unicode
    > terminology.

    While Unicode is not divided into "planes" per se, as ISO/IEC 10646 is,
    the notion of BMP characters as opposed to supplementary characters is
    such a useful one that the term "BMP" is now part of the Unicode
    lexicon. Its use with regard to Unicode is increasing, not diminishing.

    > The decision to create the BMP dates back to a time when certain
    > software suppliers were complaining that anthing approaching a full
    > implementation of ISO 10646 (later transmuted, so to speak, into
    > Unicode) would be too big for them to handle, and too costly.

    The BMP was always part of 10646.

    > Small local groups, such as ours, were then working rapidly and
    > painlessly mostly on national and international character sets on far
    > smaller scales.

    That is what companies and national organizations did, before there was
    a Universal Character Set.

    > I recall chairing some discussion at a CEN workshop, possibly in
    > Slovenia, in re something related, at the height of the debate. In any
    > case, by that time, CEN had already emerged as a big player in this
    > work (I think Unicode had yet to make much of a mark, but I don't mind
    > if someone corrects me about that, if wrong, because it really doesn't
    > matter now, in the least).
    > Anyway, it was agreed to divide ISO 10646 into sections, such as BMP
    > (Basic Multilingual Plane) and the MES (Minimum European Subset), and
    > my own company, among others, was very pleased to be hired by CEN to
    > do the necessary (a truly exciting and rewarding period, when we
    > actually got _paid_, generously, if belatedly, for such Standards
    > work!)

    This is not at all what Jill was asking about, and nobody really cares
    to hear this story again about how Marion Gunn and "her company" were
    pioneers in the development of Unicode and/or ISO/IEC 10646.

    Jill simply asked why characters have been assigned to the supplementary
    code space when there is still space left in the BMP, not why there is a
    BMP and who should get the glory for helping to build it.

    I've tried to stay out of this "taking the credit for Unicode"
    controversy, but it's starting to become a distraction to legitimate

    > Is the BMP a reality, actually referenced in software, or scheduled to
    > be so referenced in future? I doubt it, although I think that would be
    > a very good thing (just as I believe the 8859 series and the like more
    > practially useful, even today, as clean-cutting tools, than the full
    > complement of 10646, which remains a rather blunt instrument which
    > creates obstacles in unflagged text).

    Software that is sufficiently Unicode-aware frequently refers to the
    BMP. Unfortunately, a much greater proportion of software simply
    ignores the supplementary characters, and considers Unicode and the BMP
    to be one and the same. This has only been wrong for the last 12 years.

    I'm glad I don't think 8-bit character sets are more useful than the

    > Justification for saving the BMP for the purposes originally intended
    > is probably something the Unicode Consortium would be happy to clarify
    > for you.

    We've already done it.

    > Perhaps that has already been done in some of today's e-mails, which
    > are too numerous for me to read right now, under pressure of urgent
    > work. (I do promise to try to read them all.) If you want more info on
    > the purpose and genesis of the BMP, I suggest that you ask NSAI to let
    > you study the archives of NSAI/AGITS/WG6 (later transmuted into
    > NSAI/ICTSCC/SC4), or thou send a simple query directly to CEN (on
    > whose live agenda such matters remain, I believe).

    I'd be quite surprised if Jill or anyone else was really looking for

    -Doug Ewell
     Fullerton, California

    This archive was generated by hypermail 2.1.5 : Fri Mar 19 2004 - 12:05:13 EST