I think you can fill your tags at any qualifying properties, I would simply submit multiple forms if the owners are different. You're right, there isn't a place to put multiple seperate parcels that are owned by seperate people. Just make sure that the property owner is actually a lineal relative or whatever they call it. You can't hunt your aunt or uncles properties even though I know it happens all the time.

The property has to belong to you, your parents, grandparents, siblings. Thats pretty much it.