CP = common preference. common preference = a solution to a problem that all parties prefer. Not a compromise, but everyone getting what they want. This doesn't mean what they initially want, but allows for changing what is wanted.
the reason that CP is the same as non-coercion, is that in all cases where no one is coerced -- where everyone enacts one theory that has no active rivals -- then a CP happened, b/c everyone's prefered theory happens. and in all cases where someone was coerced, no CP was found, b/c someone did not prefer what happeneed.