Cocktail dress code, decoded

Knee-length to midi, in a fabric with some structure. Cocktail is the most common dress code on an invitation and the most frequently over-thought.

What it means

Cocktail sits between semi-formal and black-tie optional. It expects a dress, it expects a heel, and it does not expect a gown. The room is usually standing rather than seated, often with a drink in hand, which is why the length lands above the ankle — you will be moving.

What works

• A knee-length or midi dress with a defined waist
• Structure — a corseted bodice, a crepe that holds its line, a lined satin
• A heel you can stand in for three hours, because you will be standing
• A colour. Cocktail is the dress code with the most latitude for one

What to avoid

• Floor-length, which reads as over-formal in a standing room
• Anything shorter than just above the knee
• An unlined fabric. Overhead lighting at an evening event is unforgiving
• A clutch you cannot hold with a glass. Look for a strap

One more thing

Cocktail in a garden in June and cocktail in a hotel ballroom in December are different dresses. Let the venue set the fabric weight and the colour.