The characters 乒 and 乓 are formed by graphically altering the character 兵; 乒 omits the lower right stroke of 兵, while 乓 omits the lower left stroke. These alterations create characters that are visually similar but distinct, and they are used together as a disyllabic word primarily for their onomatopoeic resemblance to the sounds "ping" and "pong" in reference to table tennis.