Originally Posted by BenjaminNYC
O is standard on all of *A, except UA. Problem was the UA had all their own codes before the *A codes went into effect.
O-class on SK officially doesn't exist at all, I've only seen the class on domestic Norwegian flights on special tickets for the Norwegian armed forces.
The last time I flew on military duty (March '06) my e-ticket receipt actually said First Class KSU-OSL-KSU. I've saved the receipt as a souvenir: anyone having travelled domestically in Norway lately knows that our domestic services are very much one class and anything but first class!