The high-speed rail F is by the window, and D is the aisle.
Have you ever noticed that there is no E seat for the high-speed rail we usually make, why is this?
In fact, the reason is very simple, the early airplanes were mostly single-aisle, and each row generally had 6 seats, namely A, B, C, D, E, and F. where a f is by the window, c d is by the aisle, and b e is the middle.
Over time, the six letters A-F gradually formed a specific letter, representing the international practice of window, aisle and middle seat, a f is the window, and C D is the aisle.
High-speed trains have a maximum of 5 seats in a row, and in order not to affect the international practice of specific letters by the window or aisle, the number is reduced from the large letters, so there are no "e" seats on high-speed trains.
The seating layout of the second class seat is usually "3+2", which is represented by A, B, C, D, and F. A and F are window seats, C and D are aisle seats, and B is in the middle of the three-seater.
The seating layout of first class is usually "2+2", and the seats are also named after A, C, D, and F. A and C are connected together, and D and F are joined together, meaning that the first class seats are either by the window or by the aisle.
The seating layout of Business Class is usually "2+1", and A, C, and F are also used to name seats. A and C are connected together, and F is a separate seat, and the seat pitch and aisle of the business class are very spacious.