Cocktail vs. Semi Formal Attire: What's the Real Difference? Adrianna Papell The Girlfriend's Guide to Cocktail Attire: A semi formal dress code for evening events, weddings, and upscale gatherings. Think: dressy but not stuffy. Cocktail attire has fewer rules than Black Tie and White 11 Great Cocktail Dresses for Women Over 50 Sixty and Me Marsoni M251S Cocktail Short Formal Knee Length Dress Wisteria 4 What makes a dress cocktail attire? : r Weddingattireapproval 35 Best Cocktail Dresses for Wedding Guests