Thoughts on this dress for formal wedding attire. The one I bought is identical but is longer, stopping about 3 inches below the knee. : r wedding 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 Knee Length Wedding Guest Dresses Flattering Cocktail & Semi Formal Styles Ever Pretty US Blue Satin Knee Length Round Neckline Party Dress, Blue Prom Dress Bridesmaid Dress Jovani 04281 Red Short Sleeve Knee Length Dress Jovani 05016 Navy Fit and Flare Knee Length Cocktail Dress