Originally Posted by
FlightNurse
777-300 = 77w
777-300
ER = 77W
777-300 (non-ER) = 773
Pretty sure CX's regional 777-300s are the non-ER.
Also, FWIW, Cathay internally uses different designators for the 77W; I believe the 77H is the 4-class version with F and 77G is 3-class with J the top cabin.