ETIQUETTE, a term for ceremonial usage, the rules of behaviour observed in society, more particularly the formal rules of ceremony to be observed at court functions, etc., the procedure, especially with regard to precedence and promotions in an organized body or society. Professions, such as the law or medicine, observe a code of etiquette, which the members must observe as protecting the dignity of the profession and preventing injury to its members. The word is French. The O. Fr. estiquette or estiquet meant a label, or "ticket," the true English derivative. The ultimate origin is Teutonic, from sticken, to post up, stick, affix. Cotgrave explains the word in French as a billet for the benefit or advantage of him that receives it, a form of introduction and also a notice affixed at the gate of a court of law. The development of meaning in French from a label to ceremonial rules is not difficult in itself, but, as the New English Dictionary points out, the history has not been clearly established.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)