Gate card: American Airlines (AA)

The airline's policy: “Extra space during travel (AA does not use a branded 'customer of size' name on its consumer site)”

If you need more than one seat to travel comfortably and safely, AA requires you to book an additional seat by calling Reservations and to state your seating needs when booking. Reservations will provide 2 adjacent seats at the same fare. You may instead be offered a higher class of service with more space, paying the fare difference. If you didn't book an extra seat in advance, an airport agent can check whether 2 adjacent seats are available; if AA cannot accommodate you on your original flight, you can buy seats on a different flight at the same price as your original seats.

Refunds: Not published on AA's consumer pages. AA does not state any condition under which the extra seat is refunded (e.g. no Southwest-style refund policy was found).