16-character formula, esp. Mao Zedong's mantra on guerrilla warfare: 敵進我退，敵駐我擾，敵疲我打，敵退我追|敌进我退，敌驻我扰，敌疲我打，敌退我追[di2 jin4 wo3 tui4 , di2 zhu4 wo3 rao3 , di2 pi2 wo3 da3 , di2 tui4 wo3 zhui1] when the enemy advances we retreat; when the enemy makes camp we harass; when the enemy is exhausted we fight; and when the enemy retreats we pursue