What should be in a DYLAN package?

The Dylan Package should be a form of zipped folder. The contents of the folder can be varied, but is generally determined by the file extension. Within each folder is an HTML file which contains whatever metadata information the artist or packager would like to include (this can go far beyond ID3 tag info.) The header of the HTML file can include an optional XML doctype definition as well as any link to provide "live" info.

What should a DYLAN package do?