Originally Posted by
Viajero
Understood that there can be other criteria, but it seems then that one viable way to get around this problem is to deal with a central point (like the AA RTW desk), since the availability for them is not tied to the country of origin where the ticket is eventually being issued.
Well, I am not really sure what you meant by "central point". Every booking source (including the AA RTW desk) is associated with a certain city/country code. So, if you know that
for a particular flight, availability for a US-based POS is better, then yes, it would be to your advantage to book through a source that meets that criteria ...