Sentence:  The rules in this section apply to <WSD>tiedown</WSD> assemblies (including chains, cables, steel Straps, and fiber webbing), other securement devices, and attachment or fastening devices used in conjunction therewith, which are used to secure cargo to motor vehicles in transit. 
Meaning of the word marked with <WSD> tags:  A rope, strap, chain, or line used to secure a load or item.