N.Tail_End -- The .Tail_End of a .Cord is the end section which is manipulated the most while tying a .Knot. Traditionally referred to as the Working End, Running End, or Bitter End. After a .Knot is tied, the .Tail_End is part of the .Knot_Structure, but it is not part of the .Knot itself because it does not contribute to the gripping action. If two or more ends of .Cord are tied together then each end is a .Tail_End.