A Moving Rope System (MRS) has a rope folded (doubled) over a tree crotch and one end of the rope attached to the climber directly and the other side is attached via a friction hitch or device.
Background on the naming: Some folks still call this DRT, but MRS is the correct term. Background: DRT = DOUBLED Rope Technique, where “doubled” means “folded over”. In contrast DOUBLE Rope Technique (also DRT) comes from mountaineering and involves 2 separate ropes. Some call it DdRT to try to distinguish the two. But inevitably, not only was the acronym not clear, but the folks using the technique call it Double Rope Technique instead of Doubled Rope Technique.