"Mainline" and "world" sounds like BA, no one used those terms when I was in QF. It was Long or Short Haul, and the new guys were QD and latterly QCCA. "World" must have come in within the k art few years, or it's just newer crew adopting a term from another airline. Like "hatracks" which haven't been called that in QF since 1969 🤣