Amy Vanderbilt's Everyday Etiquette

America's new manners. What do you wear to a 4.PM wedding? How do you introduce a couple who are living together but not married? Should you invite an "extra" woman to dinner without an "extra" man? How do you write a letter the President of the U.S.? When a man arrives to see a woman executive, should she stand up? It is ever correct to have your elbows on the table? Should a man be invited to a bridal shower? How do you eat an artichoke?