I am only referring to one airline, but most have very similar rules. And, trust me; they do not favor the passenger.

Most of them start off giving a long list of definitions. You need to speak legalese to understand most of the terminology.

I am sure that you know that an airline can refuse you service. Here are some of the reasons:
1. If you are barefoot
2. If you have a malodorous condition
3. If you are unable to sit in a seat with the seatbelt fastened

The airline can also charge for excess amount of bags or excess weight. You need to check with the airlines, but most only allow 2 checked-in bags and one carry-on. Weight limits differ, so check before you go. Otherwise, it may cost you big bucks.

You also need to check for items that are not normal luggage. These would be items like golf bags, fishing equipment, antlers, hockey equipment and other odd items. Musical instruments, weapons, and scuba diving equipment may cost you more too.

You might also want to check and see how much the airline is liable for if your bag is lost. Check and see how much the airline will reimburse for damaged luggage also.

A very important section to check is what the airline will do for you if the flight is delayed. You may be surprised.

If your flight is delayed or canceled, consider yourself alone on an island. If it is the airline's fault, you may get some compensation if you make enough noise.

But if it is categorized a force majeure, you will basically get nothing. This is if the flight is canceled or delayed because of weather, riots, strikes, or anything beyond the airline's control.

You can try to get placed on another flight or get compensation. Persistence pays and if you are adamant enough, you may get what you want.

Be aware that the airlines are allowed to overbook their flights. So if each and every person that is booked shows up there may not be enough seats for everyone. You could get bumped.
So, what do you do if you don't get satisfaction?

You insist that you get put on another airline. You insist that you be compensated. Being persistent, not giving in, and insisting that you are a valued customer that needs to be taken care of, may get you what you deserve.

Check the airline's web site and look for the legal tab. Find the contract of carriage and check the one that pertains ? either domestic or international. Know your rights and learn how the airlines are not there to provide a service if they can avoid it.