Etiquette refers to the forms required by a good upbringing, or prescribed by authority, to be observed in social or official life; observance of the proprieties of rank and occasion; conventional decorum; ceremonial code of polite society. It commonly describes the customary behavior of members of a profession, business, law, or sports team towards each other and a label used to indicate that a letter is to be sent by airmail, which gives the term a broader and more practical sense than a single short definition would suggest. Taken together, these meanings present Etiquette as a flexible theme rather than a narrowly technical label, covering the central idea people usually mean when they use the word while still leaving room for closely related senses that appear in real language. Etiquette therefore works well as a quotation category because it can hold direct statements about the subject, figurative uses that borrow its meaning, and broader reflections that stay anchored to the same central idea. Etiquette is not limited to a single rigid definition in ordinary language, and that wider range is part of what makes the category useful for grouping related material without losing the term's main sense. When used as a theme, Etiquette can support serious, reflective, argumentative, or even playful quotations, provided the wording still connects back to the core idea described by the source definitions.
