What would be the designation for 4 parallel runways? 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?
Airports can have a left, center and right runways.  Memphis (KMEM) is a good example.  Airports with four or more parallel runways are left and right with the numbers off by one.  Los Angeles (KLAX) and Chicago (KORD) are good examples of such an arrangement.