A friend told me about paying S fare from IAD-SIN, and asked me if S fare earns miles. I remember earning miles on domestic flight but not sure about international?

Which ecomomy fare codes don't earn miles?

From what I know the ecomomy fare systems consists of:

(from high to low)

YBMHEUQVWSTKLGA

Is it safe to assume all fares above the K code earn miles on both internationla and domestic flights?

What fare code is ticket purchased at Priceline.com?