loca, maxp.numGlyphs, and TTC

[Sairus Patel]

http://www.microsoft.com/typography/otspec/loca.htm says:

> In the particular case of the last glyph(s), loca[n] will be equal the
  length of the glyph data ('glyf') table. [...] Most routines will look
  at the 'maxp' table to determine the number of glyphs in the font, but
  the value in the 'loca' table must agree.

The above implies that the first offset in 'loca' must be zero and the last offset the length of the 'glyf' table.

If this is true, then TTC components that share the same 'glyf' table must all have the same maxp.numGlyphs value. You wouldn't be able to have one component accessing glyph IDs 0-99 (maxp.numGlyphs=100) and another accessing glyph IDs 0-105 (maxp.numGlyphs=106).

Greg and others, is my reading of the 'loca' spec (and its implications for TTCs) the intended one?

And is this an implementation limit or a design point, in your opinion?
	
Thanks,

Sairus