Re: Printing and Displaying Dependent Vowels

From: Philippe Verdy (
Date: Fri Mar 26 2004 - 10:25:15 EST

  • Next message: Antoine Leca: "Re: Printing and Displaying Dependent Vowels"

    From: "Antoine Leca" <>
    > Avarangal asked about
    > > the requirements by educational establishments is the ability
    > > to print and display dependent vowels without dotted circles.
    > John Cowan answered:
    > > Avarangal scripsit:
    > >
    > >> Can any one provide information on the sequences used for diplaying
    > >> and printing dependent vowels as standalones.
    > >
    > > The standards-conforming way to do so is to precede the dependent
    > > vowel with a space character (U+0020).
    > Does it fullfil the need (i.e., displaying _without_ dotted circles).
    > If so, where is it written?

    Space is a base character, then it combines with the next diacritic with which
    it creates a "default grapheme cluster" which should be interpreted as if it was
    a single character identity. It is NOT defective. Note that NBSP can be used as
    well instead of SPACE, if you need that SPACE keeps its role of a keyword

    To display the dotted circle, you can use a defective combining sequence
    starting by the diacritic or vowel sign: for example use a control followed by
    the isolated diacritic or vowel sign, or code the diacritic or vowel sign at the
    beginning of a parsed plain-text element (in XML, HTML, XHTML or SGML, this is
    normally delimited after character entities have been parsed and resolved). You
    may also code explicitly the dotted circle symbol followed by the diacritic or
    vowel sign to create a non defective combining sequence starting by that base

    Now how would you interpret differently SPACE+diacritic or SPACE+vowel sign? If
    you display a dotted circle there, then you'll display two separate glyphs for a
    single grapheme cluster, and this is not intended by the normal Unicode
    character model. It may be useful for debugging purpose or as a help tool to
    compose text, but not to render an actual text out of an input context, and this
    should require special code in the renderer to disable that feature in fonts or
    Note that some fonts may incorrectly display SPACE+diacritic or SPACE+vowel sign
    with a dotted circle after a space. This is not a issue with Unicode but with
    the font or with the renderer.

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