"Formal Attire," "Business Casual," "Black Tie Optional"—what do they even mean? Should you go for a tuxedo or a dinner suit, or just play it safe with your trusty single-breasted number?

Pockets may trim their flaps back to lay neatly against the wind and there will be no buttons on the cuffs — no outside plumb ing. . . .” But the very latest in fashions was the cocktail suit ...