Sorry, I wasn't clear in the explanation. I'm talking about reducing the size of the RDF file by using references to other entries within the RDF file itself. For example, when I copy an entry, instead of copying all the attributes, just reference the copied entry. Then, only when I change something about the new copy will that attribute override the copied entry's attribute.
The idea here is that I can edit the parent entries which will change all the children.
To make it easier for users to understand, there could be a 'copy' mode (as it is now) and a new 'inherit' mode.