Literally, this means, “Four Directions, Five Flavors.” It is a fundamental principle to Chinese herbal medicine. Chinese herbs are categorized according to their flavor and direction of action (among other functions). The four directions are up, down, outwards, and inward/down. The five flavors are bitter, sour, salty, sweet, and pungent/acrid. The five flavors are correlated with the five Zang Fu according to Five Elements theory.