In my opinion using XML to carry date is bizarre. But then if people like to do things the hard way, I think they should. XML is much better at describing text than carrying data.
You don't invent HTML tags. You do invent XML tags. And then you have to write a parser for your tags. i4i claims they invented a new way to parse and index the tags of a markup language. I am not claiming that I agree with their claim. Nor have I said anything about the merit of their case. And yes, I do understand that you do not agree with their claim.
Well, I disagree. I got involved with ebXML because the idea has great merit. As the discussion evolved though it became obvious that attempting to standardize the definitions of electronic transactions was conceptually interesting but practically ineffective as the details and usages of all but the core elements of a transaction are context specific.
Yet, as Apple has shown, XML structures are awesome storage and transfer elements for hierarchical data. The advent of object oriented thinking and the availability of overloaded classes to manage multiple interpretations of specific data elements has created a world where XML is a great medium for carrying data.
I do not invent HTML tags because these definitions must be shared by Common Browser Interfaces that rely on standards to make possible "at least theoretically" that Safari and Firefox and Explorer can all read the same code and interpret it on the screen in the same mannor.
XML on the other hand is used for more proprietary situations where both sides of the encoding and interpreting transaction are defined by a limited number of parties, though that limited number may be in fact millions of individuals. Ultimately the effect is the same. The difference being that 2 additional contextual definition components are needed for XML, The Document Logic Definition and the Document Tag Definitions. If these definitons are shared by both sides of the interchange than XML provides the structure to carry the information in question regardless of the form or ultimate intended use.