A Contract of Carriage is a document that describes an air carriers obligation to you, the passenger, in exchange for your purchase of your airline ticket. These documents can be lengthy, but the details they contain are important. Your Contract of Carriage will tell you the airlines flight cancellation policy, and these policies vary from airline to airline. Most airlines commit to placing you on the next available flight to your destination that they operate, but they dont state that they will place you on another airlines flight if it departs sooner.
Baggage loss and damage policies are typically spelled out in extensive detail. Southwest Airlines Contract of Carriage, for example, absolves the airline from any responsibility for damage or loss to jewelry, computers, samples, artwork and much more.
Your airlines boarding policies are an important part of its Contract of Carriage. This section will spell out who may be denied the right to board, as well as which passengers may be asked to purchase a second ticket, particularly in cases where the passenger is too large to sit in a seat with the armrests down or is unable to fasten the seatbelt. Very young infants may not be able to board; people with an offensive odor may be denied boarding in certain situations.
Other key sections of your Contract of Carriage address denied boarding compensation (in other words, what happens if you are bumped from your flight), checked and carry-on baggage rules and refund policies.
Reading your Contract of Carriage requires great patience and tolerance for legalese. Still, its important to read this document, preferably before you book your flight. If problems occur, the Contract of Carriage will govern your airlines actions, so its best to know your rights if any and your responsibilities in advance.
You can find Contracts of Carriage posted at the websites of these U.S. airlines:

