There is an industry standard data model made by some gigantic multi-year committee. When I learned about it, I got all excited. These people had designed my data structure!! Woo Hoo!
Then I discovered that it's - literally - 600 pages. Fortunately, there is an xsd file. Even better, Microsoft has a utility in its developer kit (a separate download, "Power Toys") called xsd.exe. It converts an xsd file into some sort of data object class definitions. Considering all the [attributes] they stack into this file, it must have some serious .NET mojo. I don't know how to work that yet. But, I grabbed it into my Macintosh, cleaned the gigantic amount of .NET cruft and converted it into an outline program so that I can organize the class definitions.
My thought is to use the outliner format to select the subset of data elements I want to play with and then take it and convert it into javascript class definitions (ah, the wonders of bbedit and regular expressions). The same data definitions for both sides of my AJAX fence. That sounds like a great thing. I'm so excited.