<p>I believe that you can rank your schools through either ED/EA or RD. If you rank your non binding schools EA, then you can only apply to other non QB schools RD. If you rank your schools RD through QB, then you may apply to other non QB schools ED/EA. Because these schools are non binding, you could apply to other schools of your choice RD. From then, you can choose between all your EA and RD acceptances. However, if you were to apply to a binding school such as Columbia University ED or RD, then you must attend. So in our case, we would be applying to Harvard through RD, and all these QB non-binding schools through EA. This means that if you get accepted to all EA schools as well as Harvard, then you can pick from all these univeristies. But if you were to rank first to a school like Columbia ED, and you get accepted, then you must attended even if you get accepted into Harvard.</p>