Calligraphy brushwork and word usage. "Collection of Ancient and Modern Books·Dictionary of Chinese Characters·Volume 83·Collection of the Calligraphy Department·1·Essentials of the Song Dynasty Chensi Book Garden·Twenty-Four Articles of Hanlin Secret Theory on the Use of Brushstrokes": "丨, vertical method: the formula is to raise the pen and make vertical strategies The sharp edge is straight up and down, so it is used in vertical strokes in the character Shang."