Based upon my experiences performing security cooperation duties in the Military Assistance Program (MAP) in Jordan, at a GCC, and at DISAM, I offer some thoughts and comments concerning the SDO/DATT concept.
No. Barley is not wheat at all. Barley and wheat are two different species of cereal grasses belonging to the family Triticeae. Barley does belong in the wheat family, which is, as mentioned, Triticeae, but is of an entirely different species from wheat. The species name for barley is Hordeum vulgare, and the species name for wheat is Triticum aestivum. No doubt either look similar, but both are quite different from the other.
CN/HS number *. (* EU Combined Nomenclature/Harmonized System) Wheat is a type of cereal belonging to the grass family (Gramineae), the term cereals covering the grain fruits of cultivated grasses (spikes or ears in the case of wheat, rye, barley and corn; panicles in the case of oats and rice.