Labelling element precendence

Hi,

Being reasonably new to RDF, and have a question:

Is it possible to define an element such that when it is processed it takes priority over another element, despite the ordering of the elements.

The context:  

I am refining <dc:contributor> to model the specific types of contibutor, and where it might be appropriate give one type priority over another type.  ie author over illustrator.


Cheers

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