 Complete the following phrase:  By the end of the Second World War, the Group had grown to 15 squadrons. During the war, it included a significant proportion of Royal Australian Air Force or Australian-born RAF personnel, both aircrews and ground staff, who were concentrated in three Article XV squadrons: No. 455 Squadron RAAF, No. 463 Squadron RAAF and No. 467 Squadron RAAF. The Group also famously included an elite, multi-national unit: No. 617 Squadron, perhaps better known as 