According to Geoffrey Leech, there is a politeness principle with conversational maxims similar to those formulated by Paul Grice. He lists six maxims: tact, generosity, approbation, modesty, agreement, and sympathy. The first and second form a pair, as do the third and the fourth. These maxims vary from culture to culture: what may be considered polite in one culture may be strange or downright rude in another.
The Tact maxim
The tact maxim states: 'Minimize the expression of beliefs which imply cost to other; maximize the expression of beliefs which imply benefit to other.' The first part of this maxim fits in with Brown and Levinson's negative politeness strategy of minimising the imposition, and the second part reflects the positive politeness strategy of attending to the hearer's interests, wants, and needs: Could I interrupt you for a second? If I could just clarify this then.
The Generosity maxim
Leech's Generosity maxim states: 'Minimize the expression of beliefs that express or imply benefit to self; maximize the expression of beliefs that express or imply cost to self.' Unlike the tact maxim, the maxim of generosity focuses on the speaker, and says that others should be put first instead of the self. You relax and let me do the dishes. You must come and have dinner with us.
The Approbation maxim
The Approbation maxim states: 'Minimize the expression of beliefs which express dispraise of other; maximize the expression of beliefs which express approval of other.' It is preferred to praise others and if this is impossible, to sidestep the issue, to give some sort of minimal response (possibly through the use of euphemisms), or to remain silent. The first part of the maxim avoids disagreement; the second part intends to make other people feel good by showing solidarity. I heard you singing at the karaoke last night. It sounded like you were enjoying yourself! Gideon, I know you're a genius - would you...