If an airport were to have 4 parallel runways (ex if KSEA added another one), what would the designations be. Would it be 34L, CL, CR, and L? I know in Orlando they are separated by the terminals, and thus quite far apart, and they're numbered 17 and 17 and 18, for example. But if they were right next to each other, would that make a difference? Would the two-number system still be used there?