SK update:

-Y,S,B are now Economy Extra for both intra-Europe and Intercontinental.
-Y,S,B should be removed from the Economy Class line as they are featured on the Economy Extra line above (Economy Extra is a distinctive service class with separate cabin on SK).
-The order of booking classes for Economy Extra should be Y, S, B (B is used for Economy Extra Restricted and has the least availability of the three).
-W and lower could be moved to a new line called "Economy (discounted)". Same service class as Economy but typically earn less points in most programs (25% mileage in SKs own EuroBonus).
-The A class should be first in line for Business Class. It is only available long haul and is a first class priced booking class which will guarantee any traveller a seat on any SK long haul flight up to departure. The availability of A-class is always 0 in GDS-systems.