Styles for Genos 2 - Pack 171

[♝jucami]

Mr. Chello, many thanks for this great collection of Yamaha styles.
I don't have a Yamaha keyboard to test them on, but I've tried many with the Giglad software and most of them sound great. I want to buy a second hand Genos or a new Genos 2 if I can, as soon as possible.
Could you clarify something I'm curious about regarding the Yamaha style names? What do the letters and numbers that always follow the name mean? For example, S833, T550...