(a) Maxim of tact: minimize cost to other, maximize benefit to other.
(b) Maxim of generosity: minimize benefit to yourself, maximize cost to yourself. (c) Maxim of approbation: minimize dispraise to other, maximize praise to other.
(d) Maxim of modesty: minimize praise of self, maximize dispraise of self. 英文论文英汉礼貌语的对比研究(3):http://www.751com.cn/yingyu/lunwen_16823.html