That's brilliant, Norm. I hate getting summaries when I want the element names, and getting element names when I want the summaries. This solution enables me to choose what level I look at. Great idea.

Very nice! Could be useful for all sorts of indexes also.

I'm trying to think of a way to re-establish grouping after I have clicked 'X' (short of reloading the page). deleteAll() is a bit too heavy-handed; IMHO self-annihilating controls are confusing. The need for a print-friendly layout can be fulfilled with a print stylesheet (<link ... media="print"/> or @media print { ... }).

On the refentry for 'biblioid', I could not help notice that "doi" is described as "A document object identifier."

A DOI name is a "Digital Object Identifier". The object need not be a document or digitial, it is a digital identifier of any material object as well as of any abstraction (such as a unicorn or a FRBR 'work'). BTW, DOI is now an ISO Committee Draft, ISO/CD 26234.

For the next release, I'll probably make the "x" control non-destructive. I'll add enough metadata to the HTML so that I can reconstruct it in JavaScript, probably with class values on the list items or something. The ability to remove all the groupings was really an afterthought.

And I've fixed DOI, thanks!

Yes, that seems very good. Thanks for the guide, and keep up the good work! :-)