Requirements on dress to be given permission to enter a particular venue. Many nightclubs enforce a dress code in order to ensure a certain type of clientele is in attendance at the venue. Some upscale nightclubs ban attendees from wearing trainers or jeans, while other nightclubs will advertise a vague "dress to impress" dress code that allows the bouncers to discriminate at will against those vying for entry to the club. Many exceptions are made to nightclub dress codes, with denied entry usually reserved for the most glaring rule breakers or those thought to be unsuitable for the party.