List of approved tie downs per FMCSR unless excluded for particular items such as boulders or crushed cars.
Chain; Synthetic Webbing; Wire Rope; Manila Rope; Polypropylene Fiber Rope; Polyester Fiber Rope; Nylon Rope; Double Braided Nylon Rope; and Steel Strapping.
The one I can not understand is rope. The rules explicitly say no knots can be used. How the heck do you use a piece of rope without tying a knot in it.