A quirk of nomenclature and technology can lead passengers to mistakenly believe they are booking premium economy class seats when in fact they are booking much less desirable economy class seats. Delta Air Lines blames the de facto bait-and-switch on “the limitations of some current shopping experiences on third-party sites” and Google’s search engine.

A rose by any other name would smell as sweet, but depending on the airline, an economy delight seat is not nearly as sweet as a…