do not wear dinner jackets much before they are 15, or dress coat before they are about 18. Academia Some British university debating societies, such as at Oxford, Durham and University College London conduct at least some of their debates in black tie. Notably, the Cambridge Union abolished the long-standing mandatory wearing of black tie at debates in 2002. The Irish Times hosts an annual black tie debating competition. Learned societies, such as the Royal Aeronautical Society, may also follow a similar practice. Opera and ballet Historically, white tie was worn for the opera. Since the 20th century, however, black tie has been worn increasingly and today a dark lounge suit is generally acceptable. In the 21st century, many opera houses in the English-speaking world do not stipulate black tie. For example, neither the Royal Opera House nor the Sydney Opera House maintain a black tie dress code. Notwithstanding, black tie is customary at English country house operas, such as during the summer Festival at Glyndebourne. Black tie is also worn at a ballet or orchestra gala. Cruise ships At more formal dinners on cruise ships the dress code will typically be black tie although a dark lounge suit may be worn as a substitute. In 2013 Cunard, noted for its adherence to formal dress codes, relaxed its dress standards. Cunard requires one of a dinner jacket, a dark suit, formal national dress or military uniform for gentlemen diners on formal evenings. Similarly, the luxury cruise liner, Seabourn, stipulates either a dinner suit or a dark business suit on formal evenings. Weddings Black tie has been increasingly seen in the United States at weddings in place of the traditional morning dress. However, etiquette and clothing experts continue to discourage or condemn the wearing of black tie before 6 p.m. Prior to the late 1930s, black tie was even discouraged as too informal for evening weddings, with Amy Vanderbilt arguing that "no man should ever be caught in a church in a tuxedo". Emily Post would continue to argue in preference of white tie at evening weddings into the 1950s. In the United Kingdom and the rest of Europe, although a minority accepts black tie at evening wedding receptions, including some Jewish weddings, it is seldom worn at church weddings or civil ceremonies where morning dress or a lounge suit is normally favoured. Other than that, supplementary alternatives include local variations