Criteria for including characters: typographic issues

From: Jukka K. Korpela (
Date: Thu Dec 21 2006 - 14:15:37 CST

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    When reading some old messages about the proposal to encode
    Creative Commons license symbols - about which I'd rather not anything
    specific - it occurred to me that some clarification is needed about the
    character concept, from a typographic point of view.

    It seems to me that people who propose new characters that could also be
    regarded as icons forget that a character is, by essence, subject to
    typographic variation. Its particular appearance should depend on the
    particular font used, matching its design principles. Naturally its size
    varies by the font size. If text is presented in italics or in bold, such
    rendering modifications should apply to all characters in it, though
    perhaps with some reservations. If text is underlined, the underline
    crosses through the text, including special characters.

    If such variation is undesirable, or even unacceptable, then you should
    probably regard the symbol as a graphic, an image, an icon.

    What about the reservations? I recently realized that some special
    characters may need special treatment, especially in italics. Originally,
    italics means font style, a result of typographic design that uses glyphs
    that resemble handwriting to some extent. Italics letters are generally
    more slanted, but italics is far from simple slanting. However, in
    sans-serif font design, italics fonts are often rather similar to regular
    (upright) variant, just slanted, with relatively small modifications.
    Moreover, many fonts lack italics versions, and if text in such a font is
    "italicized" (using a program command or markup), programs just perform
    slanting to regular glyphs. To produce reasonably noticeable difference,
    they typically slant quite a bit.

    This means, for example, that if you have "|" and "\" in Arial Unicode MS
    (which lacks an italic variant) and italicize the text, "|" becomes
    slanted and looks more or less like "/", whereas "\" becomes roughly like
    "|" or worse. This is bad, and it should probably not happen, but it does.
    So if you managed to introduce a new special character into Unicode, is
    this what you'd like to happen to it?

    Algorithmically "italicizing" a character may obscure or distort the
    character badly, or it may just make it somewhat odd. Slanting the
    copyright sign does not make it unrecognizable, but it doesn't do any good

    I wonder how font designers decide what to do with special characters when
    designing italics fonts. Are they supposed to know or to guess whether it
    is appropriate at all to slant the character or otherwise modify it in
    italics? Some characters are "essentially vertical" (and may even have the
    word "vertical" in their name). Would it deviate from the Unicode
    principles too much to add a property that specifies whether a character
    should remain invariant in slanting?

    Jukka "Yucca" Korpela,

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