In Western clothing semi-formal is a grouping of dress codes indicating the sort of clothes worn to events with a level of protocol between informal (e.g., lounge suit) and formal. Both morning and evening semi-formal attire share design features in common with the informal lounge suit.
Whether one would choose to wear morning or evening semi-formal has traditionally been defined by whether the event will commence before or after 6:00 p.m.
In the daytime (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 a less formal version of morning dress, which features a longer, cutaway morning coat. This semi-formal ensemble is sometimes referred to as a "stroller" in North America though it is unknown in the UK, where, though the garment itself saw a limited period of popularity, was simply called black lounge. Because black was then reserved for formalwear, it was unknown as a color for lounge suits, so the term was unambiguous. In the UK this mode of dress is now extremely unusual, though some Masonic Lodges which meet during the day rather than (as is more common) in the evening do continue to specify it as their dress code. It also still is worn within the legal profession, especially by barristers. Indeed, the striped trousers are in some circles referred to as "barrister trousers". In German, a stroller is called a Stresemann, after the German foreign secretary Gustav Stresemann. Stresemann, like other German politicians of his age, wore morning dress or a frock coat in the Reichstag or when making public appearances. However, Stresemann found the long coat impractical for daily work in the Chancellery. To avoid having to change completely, he began to wear the prototype of this jacket at his office, while switching to a morning coat when engaged on more formal business. The style quickly caught on as a more practical variation on morning dress. In Japan, it is known as a "director's suit", from the term inside director.
For evening wear, the corresponding code is black tie (sometimes called tuxedo in American English). The name "black tie" for this type of evening wear can be misleading because it is a generally accepted practice to substitute other colors for the traditional black tie. In formal evening dress, or white tie dress, this practice of substituting colors in ties is much less common since men's fashion tends to follow tradition more deeply as it becomes more formal.
The origins of evening semi-formal attire date back to the later 19th century when Edward, Prince of Wales (subsequently Edward VII), 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 to Sandringham House, the Prince's hunting estate in Norfolk. 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, 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 in New York City, 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".
- Flusser, Alan (2002). Dressing the Man: Mastering the art of Permanent Fashion. New York: HarperCollins Publishers, Inc. p. 299. ISBN 0-06-019144-9.
- Flusser, Alan (2002). Dressing the Man: Mastering the art of Permanent Fashion. New York: HarperCollins Publishers, Inc. p. 240. ISBN 0-06-019144-9.
- Flusser, Alan (2002). Dressing the Man: Mastering the art of Permanent Fashion. New York: HarperCollins Publishers, Inc. p. 240, 241, 303. ISBN 0-06-019144-9.