M.E.

“Take the very word “etiquette.” From the French for “little signs,” it also connotes “social rules” both in French and in English. In fact, the two meanings share a history. King Louis XIV of France needed to give his nobles a bit of help behaving properly at his palace at Versailles, so little signs were posted telling them what was what—social dos and don’ts for dummies, so to speak.”
― Daniel Post Senning, Emily Post's Manners in a Digital World: Living Well Online