A user is looking to classify instances in a product structure based on the "product zone" so they can report on mass for each zone, and also export a lightweight CAD file for use in other behavioral simulation tools. 

I'm familiar with classifying references (physical products), but some of these physical products have multiple instances that must be classified differently.

I'm having trouble finding documentation (in the user guide at least) on the methods that allow that.

How does one classify an instance in a product structure?