Codeshares and Contracts of Carriage: Who's in charge here?

Q. I've booked a flight to Maui on Alaska Airlines, but one of the four legs of my trip will be flown on American Airlines. Which airline contract of carriage will apply for that one leg of the trip? And if different costs apply (such as the charges for luggage), do we just go by Alaska's rules even if American is our first flight of the return trip?

A. The luggage fees will be those of Alaska Airlines, since that is the carrier through which you originally booked your trip. During your segment with American Airlines, you will be covered by American's contract of carriage, should anything go wrong. If you're concerned about who would be at fault in the event that your luggage is lost, the carrier who last handled it is responsible. Also, keep in mind that the maximum liability for lost luggage under both airlines is the same, at $3,300.