The formal attire that comprises of a coat, a matching pair of pants, a shirt and a bow tie along with a cummerbund is loosely referred to as a dinner jacket in most parts of UK while in USA it is called a tuxedo. The tuxedo is now commonly referred to as the tux in almost all parts of the country and several accessories have been added to the normal tuxedo of the early ages. The vests add to the formal look to the tux. But they also allow the flexibility of taking the top coat off, when the temperatures rise, maintaining the suave look that the attire provides all the time.