Damian - it sounds to me as if the US trader is talking about pivot points. These are used by traders in the pit, and therefore used to apply particularly well to pit traded futures. When in the pits the traders could easily remember 5 numbers (R2, R1, pivot point, S1 and S2) and therefore traded between these points.
As the majority of pits have been replaced by electronic systems the pivot points are, theoretically, not as important now as they once were. However, they still have a huge following, particularly among the retail traders, so they are worth using if that is your style.
I used to bear them in mind when trading, but now I don't use them.