Oh, it gets better.

I can't remember, but there was a thread a while back about this.

V and T and whatever are not necessarily the lowest priced classes on certain routes. However, by KLM logic, the points you earn on certain routes, particularly when you combine short- and long-haul, can be based on the overall fare class.

There is then a magic formula that can be applied to average out the fare classes from two 100% classes to a single 25% class. Clever, no?

I'll see if I can dig it out.