Singapore Airlines ticket codes
This, from a recent promotion on the airline's website, shows some, or possibly all, of the different ticket class codes they use:
Economy Class (booking class / "Fare Basis Code" - M, E, B, S, or Y)
Business Class (booking class / "Fare Basis Code" - D, J, C or Z)
First Class (booking class - P or F)
Suites (booking class - R)