Such class of accommodation is abbreviated as below: 1A= First AC, 2A=2 Tier AC Sleer, 3A= 3 tier AC sleeper, CC= Chair Car, FC=First Class, SL= Sleeper Class, 2S= Second Class seat.

In the context of the Indian Railways system, 2S stands for Second Sitting, which is the lowest and most economical class of travel. Seats in 2S are typically arranged in a 3+3 bench-style layout and may or may not be cushioned; these coaches are non-air-conditioned and are primarily used for short-to-medium distance daytime journeys. In contrast, CC stands for AC Chair Car, which is a more premium, air-conditioned class of travel. CC coaches feature individual cushioned seats in a 3+2 or 2+2 layout, similar to those found on a commercial bus or an airplane. CC is the standard class for premium trains like the Shatabdi Express and Vande Bharat Express, offering a more comfortable, climate-controlled environment with fold-down trays and dedicated luggage space. While 2S is popular for budget travel and local commutes, CC is favored by business travelers and tourists for its superior comfort and amenities on daytime intercity routes.