be unloaded only at the flight's ticketed final destination. Exceptions to this requirement only occur when re-entering a country where luggage must be processed by customs agents, when changing airports, or when train travel is involved in the flight ticket. This allows a traveler to reclaim their luggage before checking in for their final destination, and simply leave the airport. Hidden-city ticketing carries the risk of the initial flight being overbooked or cancelled, and the airline transferring the passenger to a different route that bypasses the connection node. Hidden-city ticketing violates most airlines' contract of carriage. Someone doing it infrequently is unlikely, however, to be pursued by the airline, but some frequent fliers have reported either losing their frequent flier accounts or being threatened with such a loss. Experienced fliers recommend that if doing it more than very occasionally, passengers should not associate their frequent flier numbers with reservations using the hidden-city trick or should instead credit the miles to a partner airline. In 2014, United Airlines and Orbitz filed a lawsuit against Skiplagged, a flight search website focused on finding hidden-city tickets, alleging damages from lost revenues. The lawsuit was dismissed. This technique may also be used on other forms of transport where the fare charged for a longer distance is not always greater than for a shorter distance. For example, in the National Rail network in Great Britain, it is possible to buy a cheaper ticket to a further destination where a traveler has no intention to travel to, and as long as the ticket permits a break of journey, end the journey short legally. Back-to-back ticketing Back-to-back ticketing is a type of nested ticketing whereby a traveler tries to circumvent minimum stay requirements. For example, a traveler may want to make two round trips midweek in two different weeks. At one time, airlines typically charged more for midweek round trips than for trips that involved a Saturday-night stay. The back-to-back ticketing ploy allows the traveler to book two round-trip tickets with Saturday stays even though the actual travel is all midweek. If a business traveler wanted to make two round trips from New York to Los Angeles in two consecutive weeks, instead of booking two round-trips in separate weeks in the following way: Ticket A outbound: week 1, Monday, New York to Los Angeles Ticket A return: week 1, Friday, Los Angeles to New York Ticket B