Leaderboard

So you want two separate flights to be able to use the same flight number... but is there a leg designation, like Flight 331 Leg A, Flight 331 Leg B? And when you save/favorite the flight, does it book both legs? Or they both need to be done separately? The reason I ask is because if they both need to be booked together, that is fine, but just will require an additional lookup. I don't know how ACARS will handle it, though. But they should be able to just pass an additional leg option.