A twenty-foot equivalent unit is a counting convention, not a measurement. Ports, carriers and statisticians use it to express container volumes in terms of a notional twenty-foot box, a convention derived from the ISO series of container dimensions but not itself a unit ISO defines. A forty-foot container counts as two. Because the convention counts boxes rather than what is inside them, TEU throughput describes handling work at a terminal rather than the volume, weight or value of cargo moved — an empty container being repositioned counts the same as a full one, and a transhipped box may be counted more than once depending on the rules a port uses. Compare TEU figures only where you know how each was compiled.
Why nothing is quoted here. This lexicon quotes only text it has actually read, from the body that issued it. The instrument described above has a real owner, named in the paragraph, but that owner does not publish the operative wording openly, and reproductions circulating on brokers’, carriers’ and consultants’ websites are not the issuing body’s publication and are not treated as the source. So this entry describes the instrument’s role and structure and stops there. For the wording that will actually govern your transaction, go to the issuing body — and read the version your contract incorporates, since these texts are revised.