Or, Cathay or China require a round trip tix , or ticketed multiple destinations where you depart to city outside of China? ( One reason for question: found one way faires less expensive when added up than round trip or multiple destination. Second reason: would like flexibility as to from which airport depart China. Third reaosn : would like 2-3 days of flexibility as to when depart.) It seemed possible that rules may not be the same HKG, vs Chinese mainland cities.