The aircraft was being taxied to a parking bay at the completion of the flight. The pilot observed a fuel tanker parked near the edge of his taxi- path and moved the aircraft so that the nosewheel was tracking 4.6 metres to the right of the marked lead-in line. Just after this the marshaller assumed the responsibility for directing the aircraft to the parking bay. He directed the pilot to taxi straight ahead but the left wingtip struck the rear of the fuel tanker. The aircraft was stopped and the passengers and crew evacuated. The tank of the fuel tanker was damaged but not holed, and about two metres of the outboard section of the left wing of the aircraft was bent. The fuel tanker had been positioned to refuel an Australian Airlines Jetstream aircraft. The rear of the tanker encroached slightly on the taxiway. It was revealed during the investigation that groundstaff responsible for the positioning of the tanker were unaware of the correct meaning of the various taxiway markings. They had believed that the markings at the edge of the taxiway indicated the limit of the area on which servicing vehicles could be parked. The markings, in fact, indicated the limits of the full strength and low strength pavement. Both the marshaller and the pilot misjudged the clearance between the wingtip of the aircraft and the tanker.