Hi everyone,
There are many routes with their alphabet (mark), like "A" for JR Kobe Line, JR Kyoto Line, etc, and "O" for Loop Line, as well as "R" for Hanwa Line and etc...
There is a display on the train showing which type of service (like Special Rapid Service 新快速, Local 普通, etc). I wonder why are there so many types of combination for a same service, like "O"/"S" for the same type 関空快速 (Special Rapid Service), and "O"/"Q" for the same 大和路快速 (Yamatoji Rapid Service), and "O"/"P" for the same 普通 (Local) within the Loop Line, what are the differences for the different Alphabet next to the train type (種別)?
Any ideas are welcomed and appreciated. Thanks!