[xwiki-users] nested types

Hi XWiki people, I need a "semantic" way to edit xml data. This is a project that could consume a very large portion of my future time, but in the near term I'm looking for a way to get this typed data into a wiki format so that the object graph can be clicked through and offsite links can be managed. First, I need to be able to have nested types. That is, a class has a field, the type for which is a class I have defined elsewhere. I don't see a way to do this in XWiki. Am I missing something? Seems like a typing system is incomplete without being able to have classes have attributes of defined types. Travis