Dress Code in Effect

With so many different dress codes out there, it can be difficult to know what to wear, even when the type of dress requested is stated on the invitation. If you’re not certain you should always ask what to wear, especially if you’re invited to an event with an unfamiliar dress code.

Here's a handy guide to help make sense of the main dress codes in the modern day setting (from Hunt and Tannya Bernadette, Wardrobe Stylist and Fashion Marketing Graduate):

Smart Casual
Women: Wear a pencil skirt or dress pants, paired with a silk or button-down top and high heels.
Men: Opt for dressy trousers, paired with a collared shirt and loafers.
When to wear it: office parties,  business luncheons.

Dressy Casual
Women: Avoid wearing denim, tennis shoes, and cotton tees. Instead, opt for silk pants, dress pants, or a skirt. Pair with a patent leather flat, or one with nice embellishments such as a bow, buckle, or a print.
Men: Wear trousers and a dress shirt with a leather loafer, oxfords, or a slip-on shoe. Pair with a blazer or sport coat. Avoid showing up with wrinkles or clothes one size too big, too small, or in a non-coordinating color. A tie is optional.
When to wear it: religious occasion, dinner

Business Casual
Women: Put on a skirt, khakis, or dress pants paired with long sleeve or three-quarter sleeve tops. A casual dress and flats are options as well.
Men: Wear a button-down or a polo shirt, paired with khakis, or dress pants. If you so desire, layer with a v-neck sweater, a blazer, or a sport coat. A tie is optional.
When to wear it: company party, business lunch meetings.

Cocktail Attire
Women:  Wear a shorter dress with some frill. The classic little black dress makes for great cocktail attire, and is the easiest to show your personality by accessorizing to suit your mood. 
Men: Wear a dark suit, coat, and tie. Opting for dark jeans paired with a jacket and tie is also acceptable at some cocktail events, depending on how casual the atmosphere is.
When to wear it: adult birthday parties, evening social events.

Lounge
Women:  Wear a dress that would be appropriate for brunch or afternoon tea. It should fall to, or slightly above, the knee, and not be too sparkly or low-cut. Incorporate a jacket or shawl to cover the arms. 
Men: Opt for a dark suit, paired with a French-cuffed, crisp white shirt. You can go with or without a tie. Opting for a vest instead of a tie adds to the informality of the look.
When to wear it: daytime engagement parties, business breakfasts, afternoon tea.

White Tie
Women:  A floor-length ball gown is a must. Accessorize with opera length gloves, glamorous jewels, and up-do hairstyles.  
Men:  Wear a short or waist length black tailcoat (tails should reach the back of your knees,) white bow tie, starched white shirt, and a cummerbund (optional). Sport high-quality black pants.
When to wear it: charity fundraisers, government ceremonies, weddings, the theatre.

Black Tie
Women: Gussy up in a floor-length ball gown. A very dressy cocktail dress may be acceptable depending on the venue of the event. 
Men:  Wear a dark suit or a tuxedo without tails. Pair with a white shirt and a tie, or a bow tie with or without a vest and a cummerbund.
When to wear it: charity fundraisers, political dinner parties, weddings.

Creative Black Tie
Women: Dress up in a long gown, cocktail dress, or snazzy separates. Accessorize with the latest trends, such as feathers, sequins, sheer fabrics, and capes. Show off your personality with every detail.     
Men: Incorporate trendy prints in with your tie and a dressy shirt. Mix fabrics such as a silk blazer and a dress shirt to create a formal, yet interesting, look.
When to wear it: galas, weddings, and formal dinners that have a fun atmosphere.

Warm Weather Black Tie
Women: Wear a long gown with white gloves and minimal jewelry.
Men: Wear a white dinner jacket, in a worsted wool, gabardine, linen, or cotton fabric material. Pair this with a white dress shirt, bow tie, a cummerbund, and nice black leather shoes.
When to wear it: formal events that are held outdoors, such as a cruise line or country club dinners, weddings, and galas.

Black Tie Optional
Women: Look glamorous in a long gown, cocktail dress, or luxurious separates. Accessorize with items such as long gloves, clutches, and jewelry to top off the whole look.
Men: If you own a tuxedo, put it on. If not, wear a suit in a dark color such as charcoal or black, paired with a white dress shirt, and a solid colored tie. Make sure patterns are kept to a minimum and shoes are shined. Accessorize your look with a pocket square and cuff links.
When to wear it: elegant events such as galas, weddings, formal dinners.

Just to bring it all together, here's a short Guide on How to Dress Properly According to the Invitation.