Don't know about all prop shops but my experience has been that the contracts explain that you are an independent contractor not an employee, desk fees, payout scale (40% on the first $500k, 50% second $500k, 60% over a million or what ever their scale is), and commissions. They also usually include a noncompete aggreement that states that if you trade in that city that you will trade for them and if you do trade for someone else that they are entitled to their split of your profits for the remainder of the agreement. I've seen noncompetes ranging from 2 to 5 years. I have, however, heard from many sources that noncompete agreements are not enforcable in most states.