Same Itinerary?

Do the flights have to be on the same itinerary or just confirmed? I was planning a flight from Washington DC to Shanghai on 11/9/7 and then the return flight on that same ticket would be Bejing or Shanghai back to Washington DC on 12/21/17. In between I will have separate confirmed tickets on other airlines leaving Shanghai (within the 144 hours) and a flight back to Bejing (less than 72 hours before) both to/from third countries in Asia. Both directions transiting thru China to or from third countries but separate tickets.