My understanding is if you are trapping your own land and not doing anything with the animals or fur, just trapping for predator control, or whatever, you do not need a license. By commercial they mean selling the fur, selling your services, or making any money or profit from what you trap. You still need to tag your traps because if they find them they will confiscate them if they have no tags. It would be best to just buy the license because you may catch something you want to skin out and keep and it will keep you legal and not have to worry about it. You can always call and ask dcnr.