Originally Posted by
CyBeR
Yes, that is considered hidden city ticketing. No KLM is not very strict about that, except of course that you must do OSL-AMS or the rest will be cancelled.
I would use all legs except the final AMS-OSL leg. Good to know they're not very strict (have never done this before). Only worry would be that I would not be allowed to check my bag to AMS due to the long layover before I should continue to OSL.