John C Klensin writes:
Keld writes....
The term "glyph" has a distinct meaning in ISO terminology,
and it is very different form the ISO term "character".
The glyphs are representing the outlook while the character is
representing the meaning. For example the character "a" (LATIN
SMALL LETTER A) may be presented by a number of glyphs:
courier a, Times a, etc, and there is a distinctive difference between
the outlook of the italic Times "a" and the normal Times "a"
....
But, if that is the distinction (and, I agree, that is what ISO has said
that its definitions are),
(Oh, it was just my explanation of how the concepts relate, it was not
the real ISO definitions. My explanation was a bit popularized and ISO
has realized that they need clearer definitions of the terms "character"
and "glyph", and work has begun including participants from SC2 and
SC18)
then is it not the case that
(i) By making the decision that idiographic characters that "look the
same" (i.e., have the same glyphs) are coded the same way, IS 10646
becomes a "glyph standard" not a "character standard" for the subset of
languages involved?
I am not an expert on Han characters, but I believe that the
unification is done at the character level. This means that Chinese
(PRC), Taiwanese, Japanese and Korean character sets have been
tabled and characters having the same origin and almost the same
appearance have been said to be equivalent, and each of these
characters relates to a single Unihan character. This relation is
defined in ISO 10646 (at least it was in the DIS2).
So it is still the meaning that is coded, it is not the shape.
The shape may be different for different languages, there may be
a Chinese Unihan font and a Japanese Unihan font which may
differ significantly in many places.
When I am saying "meaning" it is relative... SC2 has not been willing
to allocate 'meaning' to the characters, such as "this is lowercase"
and "this is a letter" (although it is pretty obvious from the character
naming!).
Keld