Punctilious

Definitions: (1) careful in the observance of the nicer points of behavior or ceremony; etiquette; (2) very exact; scrupulous

Quote: Truly good manners are invisible: they ease the way for others, without drawing attention to themselves. It is no accident that the word “punctilious” comes from the same original root as punctuation. — Lynne Truss (1955-) English author