Because the mechanism for doing so -- application to SPACE or to NBSP -- has been specified by the standard for a decade now.
True enough, but I'm also a bit concerned about this mechanism because white space characters are another pesky thing that not all applications paint. TEX, perhaps most famously, uses its own 'glue' instead of the space glyph in the font. And what happens when word spacing is expanded or contracted in text? The diacritic mark ends up being shoved to the left or right of where it should be. Of course, if the space glyph is not painted you have to rely on blind offsets for mark positioning, because unpainted glyphs can't be found for smart positioning lookups. As someone who cares about typography, I don't like blind offsets because they don't offer precise enough control: I would much rather have a mechanism that I can reliably and precisely use with glyph positioning lookups. I'm not suggesting that the use of space/nbspace for this purpose should be deprecated, only that an alternate mechanism would be useful for those who want more control of how combining marks are rendered on a blank base.
A similar but not identical issue was raised by Peter Constable when we were talking about Qere vs Ketiv readings in Biblical Hebrew. There are cases in which vowels are applied to ellided consonants, which in some texts results in marks applied to a blank base in mid-word. In this case, my concern about using space or nbspace is that these imply a word break where there is not, in fact, any break in the word: the blank base is part of the word.
John Hudson
Tiro Typeworks www.tiro.com Vancouver, BC [EMAIL PROTECTED]
The sight of James Cox from the BBC's World at One,
interviewing Robin Oakley, CNN's man in Europe,
surrounded by a scrum of furiously scribbling print
journalists will stand for some time as the apogee of
media cannibalism.
- Emma Brockes, at the EU summit
