Q: When was the first checked bag fee?

A: American Airlines in May 2008 became the first major U.S. carrier to charge a fee for checking a suitcase. (Some discount airlines already had such a fee.) The other large airlines quickly followed.

Q: Why did the airlines do this?

A: In 2004, U.S. airlines were paying an average of $1.15 a gallon for jet fuel. By 2008, the cost had tripled.

Q: How much money does that bring in for airlines?

A: The typical bag fee is $25 for the first checked suitcase, $35 for the second. That added up to $3.4 billion last year. Airlines collected another $2.8 billion from flight change fees, typically $200.

Q: Are there other fees customers should know of?

A: Most airlines offer early boarding, priority screening and extra legroom for a fee. Some charge for advance seat assignment. Others charge to use the overhead bin. Some charge extra for water or soda.

Q: Don’t consumers know about these fees?

A: Airlines must post charts with all their fees online, but they can often be hard to find, and confusing. For instance, United Airlines charges $9 to $299 for extra legroom, the price fluctuating depending on length of the trip and demand for that flight. Passengers using Expedia, Orbitz or Kayak aren’t given the same details.

Q: How would this proposed rule change that?

A: The third-party sites and airfare search aggregators would, for the first time, have to disclose the fees.

Q: What about taxes and government fees?

A: In 2012, the DOT forced airlines to include taxes and government fees in the price shown for flights. The airlines now want Congress to reverse that rule. Stores, they argue, needn’t include sales tax in the advertised price of jeans. The bill even has its own Orwellian doublespeak name: the Transparent Airfares Act.