For example, below the level of Grandmaster, the "Ten Heavenly Stems" could be employed for classification!
The so-called "Ten Heavenly Stems" originally stemmed from the era of the Yellow Emperor. Due to the chaos brought about by Chi You, the Yellow Emperor, concerned about the suffering of his people, fought a great battle against Chi You at the plains of Zhuolu, where blood flowed for miles and could not be stanched. Thus, the Yellow Emperor fasted, bathed, built altars to worship the heavens, and performed rituals for the land. Heaven then bestowed the Ten Stems and the Twelve Branches. The Emperor arranged the Ten Stems circularly, representing the heavens, and the Twelve Branches squarely, representing the earth. Only then could the turmoil be governed. He termed it—Heavenly Stems and Earthly Branches!
