From: Asmus Freytag (email@example.com)
Date: Fri Oct 11 2002 - 23:36:37 EDT
At 08:50 AM 10/11/02 -0700, Doug Ewell wrote:
>What is the correct IBM GCGID value for U+03B8 GREEK SMALL LETTER THETA?
>Is it GT610000 or GT610002?
>The Unicode 1.1 lists (UNICHP6B.TXT and UNICHP6C.TXT) are inconsistent
>in this regard. Some entries, even within the same file, show GT610000
>while others show GT610002. The tables printed in Unicode 1.0 book are
>IBM has a Web page containing many PDF charts of code pages, and they
>have the same problem: some show one GCGID for U+03B8, others show the
Wouldn't you be able to tell by the shape associated with the GCGID?
>I suppose this might have had something to do with confusion over U+03D1
>GREEK THETA SYMBOL, but that character (a glyph variant of U+03B8) has
>been in Unicode since 1.0. Was there some dispute at that time over the
>preferred glyphs for U+03B8 and U+03D1? I remember that they were
>swapped in Unicode at one point. Was the inconsistency in GCGID a
>precursor to the decision to swap glyphs?
They were swapped in Unicode 3.0 / second edition ISO 10646 to make the
alphabetic sequence match the usage in typical Greek Text using an ordinary
serifed typestyle, reserving the other code point (U+03D1) for the symbol
as it shows in mathematical usage. (Some text fonts will use a form
matching 03D1 for 03B8, but that's OK - those fonts are fully usable for
text, just not for math).
Historically, as far as I can tell, this relates to the fact that SC2 has
documented its 8-bit character set standard with sans-serif type style(s)
but 10646 and Unicode are using a serifed type style for the representative
glyphs. Sans-serif fonts often contain the straight theta instead of the
loopy one. As long as (small) character sets were only intended for text
usage, any theta will do - Unicode and 10646 must be usable for both text
*and* technical notation(s). That's where precise choice of representative
glyph begins to matter. (The same is true for 0061 showing a hooked lower
case a in distinction to the round lower case a for IPA. A font for non-IPA
usage is free to use either form for 0061, but a font that needs to support
or at least enable IPA usage is limited to the hooked form.).
>Any ideas? (It's probably best not to ask why I am paying attention to
>GCGIDs in the first place.)
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