Re: [xml-dev] RE: Dealing with lots of chunks of highly interrelated data?

For your point 3, even xml hierarchy does not provide any semantics including that there  is necessarily some hierarchy implied by XML containment. Not even generic ones like connects-to, has-a, is-a. It is no different to IDREF or a URL. XML is just a transfer syntax to go from common bytes to some useful graph-structures. (And back?)

Consider a document format that has page-break marker elements in otherwise semantic but sequential markup: the pagebreak attaches more to a position in the data content of an element than being in any 'semantic' relationship to the element. (And,yes, better as a PI probably, in the abstract.)

Regards
Rick