Paired Pools

I know paired pools have to have a 1:1 releationship, but is there anthing that says if you you want to use pool pairing that you have to pair all of your pools?

For example I have 3 sites A, B, and C.  Each has 1 pool.  I am only concerned about DR for Sites/Pools A and B.  Can I setup A and B as a pair and leave C unpaired?

Thanks,

Paul MacLean