Bobistheoilguy is what I'd specifically recommend to learn about those terms, as well as oils available all over the world. Things like: tbn (total base number, basically how "basic" the oil is when new, to buffer increasing acidity as you go through your change interval), cSt @ 100 (centistokes @ 100 degrees C, basically your viscosity (thickness) at operating temp), cSt @ 40 (same thing, only when cool. The difference between the two being very important)
IIRC they have forums dedicated to specific regions.
My main point is on that website the entire reason for the site & forums is lubrication performance, with actual tribologists (look it up.. it's relevant) frequently contributing to the discussion.. when you combine that focus with the depth of data (THOUSANDS of used oil reports have been posted with data logged and categorized) you can make a very informed decision on which oil will work best for you.
Thing is, it requires taking the time and effort to educate yourself. If you aren't gonna do that, you should probably just stick with what KTM recommends.
In my case, I'm comfortable running any oil of the recommended viscosity that is JASO-MA/MA2 certified. For me, the importance of the oil performance within our clutch and transmission justifies seeking out that specific certification. On synth/dino: to get 10w-50, it basically has to be synthetic in the first place. Those requirements leave me with only 3 or 4 possible oils.. but that's plenty.
The guys running Delo & Rotella are using outstanding oils.. That said, even with them being designed for extended drain intervals (to mitigate the reduced performance after mechanical shear over the life of the oil) I just don't feel comfortable using something that wasn't designed for a gearbox.