Middle of page 14 (15 of the .pdf file): "Single one-way trip." "One way upgrade." Your itin. lists four one-way trips, since it's generally impossible to cross the same ocean twice and call it a one-way trip. Don't care whether it appears to be a multi-city or return trip. Four one way trips require four certs. Always have, probably always will. Bouncing around between hubs on either end of the trip don't usually cause a one-way trip to become two one way trips, but crossing the same ocean always does.