Civility.

Stuart, George Washington, 1795

Fourteen year-old George Washington's Rules for Civility ...

These maxims originated in the late sixteenth century in France and were popularly circulated during Washington's time. This exercise, now regarded as a formative influence in the development of his character, included guidelines for behavior in pleasant company, appropriate actions in formal situations, and general courtesies.

My favorite ...

While someone is Speaking, raise not your Index finger while checking your electronic  interrupter.

Goofus.

Air.

Barry, Portrait of Edmund Burke, Statesman, Orator and Writer, 1774

Manners are of more importance than laws. Manners are what vex or soothe, corrupt or purify, exalt or debase, barbarize or refine us, by a constant, steady, uniform, insensible operation, like that of the air we breathe.

Edmund Burke

Inform.

Roslin, King Gustav III and His Brothers (detail), 1771

William Penn's "Rules of Conversation", from Fruits of Solitude

1. Avoid Company where it is not profitable or necessary; and in those Occasions speak little, and last.  
2. Silence is Wisdom, where Speaking is Folly; and always safe.   
3. Some are so Foolish as to interrupt and anticipate those that speak, instead of hearing and thinking before they answer; which is uncivil as well as silly.   
4. If thou thinkest twice, before thou speakest once, thou wilt speak twice the better for it.   
5. Better say nothing than not to the Purpose. And to speak pertinently, consider both what is fit, and when it is fit to speak.   
6. In all Debates, let Truth be thy Aim, not Victory, or an unjust Interest: And endeavor to gain, rather than to expose thy Antagonist.   
7. Give no Advantage in Argument, nor lose any that is offered. This is a Benefit which arises from Temper.   
8. Don’t use thy self to dispute against thine own Judgment, to shew Wit, lest it prepare thee to be too indifferent about what is Right: Nor against another Man, to vex him, or for mere Trial of Skill; since to inform, or to be informed, ought to be the End of all Conferences.   
9. Men are too apt to be concerned for their Credit, more than for the Cause.