Boarding pass & class explanation needed
 

See attached photo of two SAS and two Norwegian boarding passes. Notice that they both have a class field with two letters - one big and fat to the left and another a little smaller to the right.

As far as I know (on SAS at least), it's the smaller one to the right that is used in the milage calculation. But I'm not sure if this is the same with Norwegian?

I'd would be awesome if someone here knew more about this :)

Bonus: If someone could explain a few of the more exotic fields like "Notes" and "Sequence" as well, it would be cool

The sequence number is simply the order in which customers checked in for the flight. Seq 00002 means that you were the second to check in.

The SK*S in the Notes section indicates that you have Star Alliance Silver (*S) status from SAS (SK). LH*G would be Lufthansa (LH) Gold (*G).

El_Duderito: Thanks a lot for the explanation :) Do you know anything about the class fields as well?

The second letter in the class is the booking class, the first is the cabin.
f = first, c = biz, y = coach (m = main = coach)

You did a good thing by blacking out all personal info.

BTW. here's a nice IATA guide on what is the format of the 2D barcodes. Many airlines now use encrypted barcodes that you won't necessarily be able to reproduce yourself, but there are still some that are doing plain-text barcodes.