Q. My husband and I are flying to Canada. Our tickets show that we are booked on Air Canada for our flight home. Because it is a code share, we will actually be on a United flight. Air Canada allows you to check a bag without charging a fee. United does not. Which rules apply?

A. Here's what Air Canada has to say about this on their site:

Because each airline has its own terms and conditions of carriage, whenever you are traveling on a flight operated by one of Air Canada's code share partners, you may be subject to terms and conditions that differ from those of Air Canada. If is therefore important to familiarize yourself with the operating carrier's terms and conditions, including those regarding:

Check-in times and procedures

Carry-on and checked baggage