What exactly is a "representative glyph"? (referring to U+2591, emoji, and other characters)

From: Karl Pentzlin (karl-pentzlin@acssoft.de)
Date: Sun Jan 04 2009 - 12:49:22 CST

  • Next message: Jukka K. Korpela: "Re: What exactly is a "representative glyph"? (referring to U+2591, emoji, and other characters)"

    Neither the "glossary" nor the "general index" of the printed Unicode
    5.0 edition lists the term "representative glyph".

    The printed Unicode 5.0 edition says on p.564 within section 17.1,
     below the header "Images in the Code Charts and Character Lists":
    "Each character in these code charts is shown with a representative
     glyph. A representative glyph is not a prescriptive form of the
     character, but rather one that enables recognition of the intended
     character to a knowledgeable user and facilitates lookup of the
     character in the code charts."

    Did I overlook a more concise definition somewhere?

    Are the following statements true?

    1. The representative glyph of U+0323 COMBINING DOT BELOW is a dotted
       ring on the baseline with a dot beneath of it.
    2. The representative glyph of U+0020 SPACE is a Latin letter pair
       "SP" surrounded by a dotted square.
    3. Representative glyphs are always printable using black color on
       white background, without using gray shades and/or other colors.
    4. The representative glyph of a character is not necessarily a valid
       visual representation of the character itself to be used within its
       plain text use.
       This especially applies to control codes and space characters which
       have no glyphic representation by nature, but also for some special
       cases where the glyphic representation of the character cannot be
       expressed unambiguously within its block by a glyph printable black
       on white, e.g. for U+2011 NON_BREAKING HYPHEN or U+2591 LIGHT SHADE
       (the latter one being a gray shade by nature and by its correct
    5. The representative glyph does not denote the character
       unambiguously (e.g. U+0042/U+0392/U+0412).
    6. The reference glyph of the emoji e-B16 (purple heart) may be a
       black and white striped heart (either devised by a scheme to
       represent colors within black and white presentations, like
       heraldry, or simply by a particular decision).
       While the name "STRIPED HEART" is misleading, a it would refer
       to the representative glyph instead of the character itself,
       "EMOJI SYMBOL PURPLE HEART" would be a correct name which denotes
       the identity of the symbol.
    7. If someone provides evidence for a real "STRIPED HEART" symbol,
       he may propose it, using the same representative glyph as for the
       purple heart.

    - Karl Pentzlin

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