Most importantly, perhaps, it does not charge for checked-in luggage.

可能最重要的，西南航空不为托运行李收费。

youdao

The charge for overweight luggage is 5 dollars per kilo. You should have excess luggage checked.

超重行李的费用是每公斤5美元。你须得托运超重行李。

youdao

Clearly, I think, the message is there -- if you want to annoy people charge for luggage.

我认为，事情是明摆着的：如果你想惹人烦，那就向他们收行李费吧，”他说。

youdao

The luggage charge is only for really big luggage.

FORBES: A Guide to Riding Taxis in the District of Columbia

In practice, cabbies often will try to charge you for luggage below this size, luggage you place in the back seat, groceries in the trunk, etc.

FORBES: A Guide to Riding Taxis in the District of Columbia

Buying a ticket now is the equivalent of a down payment, Boyd says, as airlines look for ways to charge passengers for everything from water to luggage.

FORBES: Magazine Article