 According to "The Ashley Book of Knots", "The purpose of a "whipping" is to prevent the end of a rope from fraying ... A whipping should be, in width, about equal to the diameter of the rope on which it is put ... [Two sailmaker's whippings], a short distance apart, are put in the ends of every reef point, where the constant "whipping" against the sail makes the wear excessive; this is said to be the source of the name "whipping".