Re: [OpenType] PS glyph `phi' vs `phi1'

From: John H. Jenkins (
Date: Wed Feb 19 2003 - 18:56:39 EST

  • Next message: Asmus Freytag: "Re: [OpenType] PS glyph `phi' vs `phi1'"

    On Wednesday, February 19, 2003, at 04:13 PM, Werner LEMBERG wrote:

    > I have to correct myself, fortunately. After looking into the printed
    > version of Unicode 2.0 I see that the glyphs of 03D5 and 03C6 in the
    > file U0370.pdf are exchanged. Your assuption is correct that the
    > annotation in Unicode 3.2 is wrong.

    I'm sorry, but you've lost me here. The Unicode 3.2 text states:


    With Unicode 3.0 and the concurrent second edition of ISO/IEC 10646-1,
    the representative glyphs for U+03C6 GREEK LETTER SMALL PHI and U+03D5
    GREEK PHI SYMBOL were swapped. In ordinary Greek text, the character
    U+03C6 is used exclusively, although this characters has considerably
    glyphic variation, sometimes represented with a glyph more like the
    representative glyph shown for U+03C6 (the “loopy” form) and less often
    with a glyph more like the representative glyph shown for U+03D5 (the
    “straight” form).

    For mathematical and technical use, the straight form of the small phi
    is an important symbol and needs to be consistently distinguishable
    from the loopy form. The straight form phi glyph is used as the
    representative glyph for the symbol phi at U+03D5 to satisfy this

    The reversed assignment of representative glyphs in versions of the
    Unicode Standard prior to Unicode 3.0 had the problem that the
    character explicitly identified as the mathematical symbol did not have
    the straight form of the character that is the preferred glyph for that
    use. Furthermore, it made it unnecessarily difficult for general
    purpose fonts supporting ordinary Greek text to also add support for
    Greek letters used as mathematical symbols. This resulted from the fact
    that many of those fonts already used the loopy form glyph for U+03C6,
    as preferred for Greek body text; to support the phi symbol as well,
    they would have had to disrupt glyph choices already optimized for
    Greek text.

    When mapping symbol sets or SGML entities to the Unicode Standard, it
    is important to make sure that codes or entities that require the
    straight form of the phi symbol be mapped to U+03D5 and not to U+03C6.
    Mapping to the latter should be reserved for codes or entities that
    represent the small phi as used in ordinary Greek text.

    Fonts used primarily for Greek text may use either glyph form for
    U+03C6, but fonts that also intend to support technical use of the
    Greek letters should use the loopy form to ensure appropriate contrast
    with the straight form used for U+03D5.


    What annotation in 3.2 do you feel is incorrect?

    John H. Jenkins

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