Thank you all for the clarity with which you've explained the rules, particularly 4.g.

An excellent idea from pandaperth (as so often on these pages). Since they don't have a dedicated RTW desk, BA are always extremely slow at reacting to changes made to RTWs. They always insist on the reservation being sent to their fares dept before being ratified, even when no change fees are involved (e.g. just changing dates). In my case I needed to change plans within hours to get to TPA and so grabbed one of the few remaining tickets at the back of the plane.

A pleasant outcome: BA deserve credit for stepping up to the plate. After much to-ing and fro-ing between a Gold line supervisor and the fares dept, they eventually agreed to waive 4.g in this particular case as there were compassionate reasons involved. In a way, a win-win situation. I avoided the inconvenience, time and extra cost of having to travel nearly 5,000 unnecessary miles; BA avoided having to give me 20K Avios and have three seats available for re-sale, including a long-haul flight.

I don't often praise BA, but in this case they showed the kind of flexibility that does a lot to cement customer loyalty. A huge pat on the back to Natasha on the Manchester Gold line for her obstinate persistence in obtaining a favourable outcome.