From: Philippe Verdy (email@example.com)
Date: Mon May 03 2004 - 05:44:04 CDT
From: "D. Starner" <firstname.lastname@example.org>
> Unicode will not allocate any more codes for characters that can be made
> precomposed, as it would disrupt normalization.
But what about characters that may theorically be composed with combining
sequences, but almost always fail to be represented successfully?
If normalization stability is a legitimate goal, this should not prevent some
precomposed characters to be encoded separately without any canonical
equivalence with their logically decomposed equivalents.
This is already true for combining overlay diacritics (single or double strokes,
vertical bars, and horizontal bar), or for diacritics that form a ligature with
the base letter (such as combining horns and cedillas...), where the logically
"composed" characters should better have their own codepoint.
If such ligature has a distinct semantic from a ligature created by ligaturing
separate letters for presentation purpose, the character is not a ligature (the
AE and OE "ligated glyphs" are distinct abstract characters) .
The case of dot below however should be handled in fonts by proper glyph
positioning and probably not by new assigned codepoints, unless this is only one
possible presentation form for an actual distinct abstract character that may
have other forms without this separate diacritic (for example if g with dot
below was only one presentation for an abstract character that may be also
renderd with a small gamma)....
We have already some examples of characters that have exactly the same glyphs
but are distinct semantically due to their case mappings (see the glyph showing
a barred D for example, or the turned E: their apparence may be identical but
they have distinct semantics and properties).
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