Women Floral Semi Formal Dress Mommy and Me Hayden Girls Semi Formal dress code guidance. For dresses: no spaghetti straps, no strapless, and no one shoulder or off shoulder dresses. Length must be fingertip length. No shorts or blue jeans. If you Which dress looks the best and is most appropriate for semi formal dress code? : r Weddingattireapproval 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