thanks so much for your replies. I would imagine the ONEWORLD would have a standard procedure for baggage tagging and handling. I suspect that rules sometimes change due to the different requirements of countries and airports. I have done USA -HONG KONG-SIN without having to go through costumes or immigration in Hong Kong. I believe though that this is only possible due to the rapid and efficient Hong Kong airport organization. In the Us, I always have to collect my bags and then recheck them after costums and immigration for my onward international flight. I wonder if SIN airport is as efficient as Hong Kongs?