the ticketing system for some 2A coach seating arrangements are like , from seat no 1 - seat no 42 all bays will have 6 berths(4 Inside + 2 outside(SL/SU)each separated by curtains - and the last bay(Smaller when compared with other bays and will be like a first class coupe with only 2 Berths inside and 2 outside(SL/SU) separated by curtains ) will be like 43-Lower , 44-Upper , 45-Side Lower , 46-Side Upper . but in some coaches the last bay will be of 4 berths only like 43-Lower , 44-Upper , 45-Lower , 46-Upper and the space in SL and SU berths will be blank .