Following several comments from the list:

Any and all comments about the syntax in my document and examples: I SHOULD have said that I'm not trying to make this "proper" XML yet. My intention is just to determine the data elements needed - it seems to me that once we've done that the best-practice XML (e.g. should this data element be content or attribute) can be done by you people with the knowledge to do it properly.

So please read anything that looks like XML in the examples as pseudo-XML. Perhaps there's a better way of writing the examples to make it clear they're not supposed to be XML yet. I'm sure I'm going to regret not having done this.

Cheers - k