Fashion Bigwigs Weigh In On the Rules of Formal Attire and Black Tie

Parties are a time to let loose, enjoy a cocktail, and hobnob with other revelers. However, they are not all one and the same. Some are formal affairs set in glittering ballrooms or dining halls. Others are laid-back and held at lofts or restaurants. Either way, it is always important to dress for the occasion at hand, and an astute host or hostess will set forth directions on the proper attire. This is when it can get tricky.

Once the rules are set, it is up to you, the guest, to decipher what they mean. The usual suspects: white tie (larger-than-life gowns), black tie (elegant evening dresses or tuxedos, usually in black), cocktail (sleek, flirty frocks or jumpsuits), and casual (fitted trousers or jeans with nifty tops). These dress codes offer concise guidelines highlighting the vibe of the soiree. And though these descriptors leave room for interpretation, they have set parameters that are easy to follow. But then, there are the style conventions that are utterly baffling—namely, black-tie optional.

What’s the deal with the word optional? Black tie already comes with its own baggage. Factor in the optional bit, and you’re faced with another style quandary. At the very least, it should be understood that it stands for formal attire. The only caveat is how formal. What are the limits?

The right answer, to be sure, is not a simple one, nor is it easy to come by. So to help us solve this dilemma, we’ve culled experts, bigwig retailers, and style directors at some of the largest department stores and online platforms. They are surrounded by fashion all day, every day, buying clothes that will appeal to women for a number of events—including parties that have the ever-confusing mandate: black-tie optional.