Frank wrote:

> in other words, somewhere there has to be a knowledgeable 
> instance that decides
> what to do when a current font selection doesn't work for the 
> requested
> characters because it is not part of the supported glyph set 
> of that resource
> --- you can consider that part of the font selection 
> intelligence and it is
> not resolved with a naming standard for characters eg unicode

Is that not what virtual fonts are for?