Molakule:
I would suggest that either its is a re-named product (i.e. RS-the 'S') or, its a typo. And yes, I still say its a real syn. because of the way oils are marketed there. I know that in Germany, where they are required to specify (ie. HC Synthetics or Full Synthetics) type of oil, its listed a a full syn. and not an HC syn. Of course this may only be in Germany. However, I do ask this: "Is the Formula 'R' available in a 10w-60 too.?" If so then, this would probably be the formulation as sold in Europe. Perhaps, and perhaps not.