A method commonly used by airline passengers to get cheaper fares is at the center of a court row between a German airline and one of its customers.
Lufthansa has taken a passenger, who didn't show up for the last leg of his ticketed journey, to court in an apparent bid to clamp down on "hidden city" ticketing.
The practice involves passengers leaving their journey at a layover point, instead of making a final connection.
For instance, someone flying from New York to San Francisco could book a cheaper trip from New York to Lake Tahoe with a layover in San Francisco and get off there, without bothering to take the last leg of the flight.
According to a court document, an unnamed male passenger booked a return flight from Oslo to Seattle, which had a layover in Frankfurt. The passenger used all legs of the outbound flight, but did not catch the Frankfurt to Oslo return flight. He instead flew on a separate Lufthansa reservation from Frankfurt to Berlin.
Lufthansa saw this as a violation of their terms and conditions and is seeking €2,112 (around $2,385) in compensation.
A Berlin district court dismissed the lawsuit in December, but Lufthansa's spokesperson confirmed to CNN that the company has "already filed the appeal against the decision."
Back in 2014, United Airlines and Orbitz filed a civil lawsuit against 22-year-old Aktarer Zaman, who founded the website Skiplagged.com, which helps travelers find cheaper flights by using the "hidden city" strategy.
The case was thrown out in 2015 after the judge in the Northern District Court of Illinois said the court didn't have jurisdiction over the case because Zaman didn't live or do business in that city.