In this scenario agreed, 100% but this is what I've been told by call centre staff. I think what they mean by linked is include a comment in each booking referring to the other and the connecting nature if their itineraries. Doesn't create any obligation for the airline to do anything in the event of delay etc.This is incorrect. Booked flights cannot be linked.
If a booking has travel on say QF & AA, there would be a separate AA booking/reloc to the QF one as AA is hosted on a different system to QF. Technically, these bookings are said to be linked.
