> In addition to merely stamp the language label on a string, I think
> that
> possibly one may have to stack it, that is, if there is a quote of
> French
> within English, then one can from within the French quote know that
> it is
> within an English quote.

Frank's new LaTeX language model supports something quite
sophisticated in this direction but this is for structured documents.

It is not clear that informastion about the hierarchy makes sense
when attached to an arbitrary text string since that may well get
removed from its plqace in the hierarchy.

We have two _different_ things here, both naturally called language
labels, whose values are closely related).