I'm afraid not! I'm only getting a tiny better grip on the form, I know now that these 'tax treaty benefits' are there so you don't have to pay tax both in the U.S. and the Netherlands. Also, Apple emailed me that I have to read their pdf files (which are on the online tax form), but they are too technical for me. I'm looking right now for a Dutch developer who already filled in the form and could hopefully help me...