Have you found a way tp do this for excluding two different booking classes?

I am trying to scan QR business class fares that allow the passenger to do free seat assignment and get lounge access. QR has two restricted business booking classes (P and R). I am trying to say I don't want P and I don't want R.

I've tried every combination I can think of and nothing seems to work. I could use F BC=I|BC=C|BC=D|BC=J but that will only work as long as QR doesn;t change their other business booking classes. ANd it is easier to ray not one of two rather than any of of four booking classes.