The original Pendolino design was for an 8-car train that could be extended to 9-car or 10-car by the addition of extra trailer vehicles in the middle of the unit.
The 8-cars were labelled A,B,C,D,G,H,J,K, leaving a gap for E and F for 9-car and 10-car versions. G,H,J and K were all first class...