Originally Posted by
corporate-wage-slave
If it is one ticket then it can't be HBO, HBO is not combinable. Technically an agent could plug 2 non combinable tickets together "illegally" but Expedia doesn't do that. I would read this as a BA non HBO ticket going out, and an AB non HBO coming back. Air Berlin may give you the BA allowance but I can see the agent in Rhodes would simply enforce AB's rules. Luckily AB is more or less the same as BA, with the exception of hand luggage.
Before booking with Expedia, give BA a ring to see if they can book the ticket for you, doesn't always work, but it may do, and it gives you a lot more protection if something goes wrong.
Thank you for your reply. I spent some more time on this and it seems that Expedia is actually selling two one-way fares in one ticket. The outbound (LHR-BA-DUS-AB-RHO) is an AB Q fare that seems to include a bag and the return (RHO-BA-LGW) is a BA N fare that is HBO. Interestingly the outbound is not available on the AB site, which doesn't offer the BA flight. In any case, I think I will book these as two separate tickets to remove all uncertainty.