It's not a train. Because... KKL" Is not a train in any form or code, we can not find such an abbreviation or code in any train system or database.
Many train codes or abbreviations are determined by specific rules and systems, such as T, K, Z, D, G, and so on.
Different codenames or abbreviations represent different train types, speeds, classes, facilities, services, etc.
If we are going to describe or inquire about a train by a code name or abbreviation, we need to understand and follow the corresponding rules and regulations.
It is the train we usually take, the bullet train is the beginning of the D, the high-speed rail is the beginning of the G