Hi, we recently bought a RT ticket-set from San Diego to Osaka Japan. I was a bit surprised to see an AS3380 "Alaska Skywest" as the initial outbound domestic leg of our trip from San Diego to San Francisco; I do not see that Alaska Airlines is a partner with United (so wondering how they have a baggage share agreement?). And so on getting our ticket, we were given a notice to expect a $35 domestic baggage fee for this leg of our trip. We bought the ticket on https://www.united.com with 6 different legs. I called and was quoted US Department of Transportation regulation about origin flight airline may levy their own baggage fees. The rest of the flight has ANA or United flights. Is this something new? I thought when purchasing on united.com, everything is codeshared. If there is no codeshare, how are they moving luggage during International Connection? Do we have any recourse? Thanks.