The hull is not good to eat. For flour we want to start with the unbroken kernel because the oils and other nutrients start to lose their potency once the kernels are broken, smashed, ground or milled. Grains have bran, where the fiber and B Vitamins are. The bran is very important to eat. When the bran is removed the grain is called pearled or polished.
White flour is made from wheat that has the bran and wheat germ removed.
Hulled Barley , Is browner in color than pearled, meaning more of the bran is left on the kernels. Hulled Buckwheat , is not a wheat. It is a separate seed. Hulled roasted buckwheat is called kasha. For flour we want it raw.