In Western clothing semi-formal is a grouping of dress codes

Dress code (Western)

A dress code is a set of rules governing what garments may be worn together and in what setting. Examples of dress codes are combinations such as "smart casual", or "morning dress". A classification of these codes is normally made for varying levels of formality and times of day...

, indicating the sort of clothes worn to events with a level of protocol

Etiquette

Etiquette is a code of behavior that delineates expectations for social behavior according to contemporary conventional norms within a society, social class, or group...

 between informal

Informal attire

Informal attire, also called international business attire or Western business attire is a dress code, typified by a suit and necktie, for men. On the scale of formality, informal attire is more formal than casual but less formal than semi-formal. It is more presentational than semi-casual, but...

 (e.g. lounge suit) and formal

Formal wear

Formal wear and formal dress are the general terms for clothing suitable for formal social events, such as a wedding, formal garden party or dinner, débutante cotillion, dance, or race...

. Historically there were both day and evening semi-formal dress codes, but this category is now seen almost exclusively in the context of evening wear.

Background

The origins of semi-formal attire date back to the 1800s when Edward VII, the Prince of Wales

Prince of Wales

Prince of Wales is a title traditionally granted to the heir apparent to the reigning monarch of the United Kingdom of Great Britain and Northern Ireland and the 15 other independent Commonwealth realms...

, wanted a more comfortable dinner attire than the swallowtail coat.

In the spring of 1886, the Prince invited James Potter, a rich New Yorker, and his wife, Cora

Mrs Brown-Potter

Cora Urquhart Brown-Potter , was one of the first American society women to become a stage actress.-Biography:...

, to Sandringham House

Sandringham House

Sandringham House is a country house on of land near the village of Sandringham in Norfolk, England. The house is privately owned by the British Royal Family and is located on the royal Sandringham Estate, which lies within the Norfolk Coast Area of Outstanding Natural Beauty.-History and current...

, the Prince's hunting estate in Norfolk

Norfolk

Norfolk is a low-lying county in the East of England. It has borders with Lincolnshire to the west, Cambridgeshire to the west and southwest and Suffolk to the south. Its northern and eastern boundaries are the North Sea coast and to the north-west the county is bordered by The Wash. The county...

. When Potter asked for the Prince's dinner dress code, the Prince sent him to his tailor, Henry Poole & Co., in London, where he was given a suit made to the Prince's specifications with the dinner jacket.

On returning to Tuxedo Park, New York

Tuxedo Park, New York

Tuxedo Park is a village in Orange County, New York, United States. The population was 731 at the 2000 census. It is part of the Poughkeepsie–Newburgh–Middletown, NY Metropolitan Statistical Area as well as the larger New York–Newark–Bridgeport, NY-NJ-CT-PA Combined...

, in 1886, Potter's dinner suit proved popular at the Tuxedo Park Club. Not long afterward, when a group of men from the club chose to wear such suits to a dinner at Delmonico's Restaurant

Delmonico's Restaurant

Delmonico's is the name of series of restaurants of varying duration, quality, and fame located in New York City. The original and most famous was operated by the Delmonico family during the 19th and early 20th centuries, closing due to a Prohibition-era slowdown in 1923...

 in New York City

New York City

New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...

, other diners were surprised. They were told that such clothing was popular at Tuxedo Park, so the particular cut then became known as the "Tuxedo".

From its creation into the 1920s, this dinner jacket was considered appropriate dress for dining in one's home or club, while the tailcoat remained in place as appropriate for public appearance.

Traditional use

In the day time (before six o'clock) the semi-formal code requires for men a black tail-less coat with formal (striped or checked) trousers (this combination is morning dress

Morning dress

Morning dress is the daytime formal dress code, consisting chiefly for men of a morning coat, waistcoat, and striped trousers, and an appropriate dress for women...

, sometimes referred to as the "stroller

Stroller (style)

The stroller, also known as a Stresemann, a director, or simply black lounge is a form of men's semi-formal daytime dress comprising a single- or double-breasted coat , grey striped or checked formal trousers, a necktie , and a waistcoat...

" in America). For evening wear, the corresponding code is black tie

Black tie

Black tie is a dress code for evening events and social functions. For a man, the main component is a usually black jacket, known as a dinner jacket or tuxedo...

 (often simply tuxedo in American English);

Colloquial use

The traditional interpretation of dress codes in different social settings and continents now varies, so much so that use of the term 'semi-formal' will often lead to confusion. With the use of full-formal attire such as 'white-tie' or 'morning dress' less common, traditionally defined attire such as 'black-tie' is perceived simply as 'formal', leaving 'informal' and 'semi-formal' as somewhat interchangeable terms.

Women

For semi-formal occasions, women usually wear a cocktail dress

Cocktail dress

A cocktail dress or cocktail gown is a woman's dress worn at cocktail parties, and semi-formal, or "black tie" occasions.The length of cocktail dresses varies depending on fashion and local custom. The length ranges from just above the knee to touching the ankle...

, as a long evening gown

Evening gown

An evening gown is a long flowing women's dress usually worn to a formal affair. It ranges from tea and ballerina to full-length. Evening gowns are often made of a luxury fabric such as chiffon, velvet, satin, or silk...

is formal attire.