Check (pattern) a board used for playing checkers and chess, and in heraldry. The check pattern has a number of symbolic meanings. In auto racing, the chequered flag is displayed at the finishing line to signal that the race has finished. It originates from the "checkers" who watched the finishing line and checked when cars had finished the race. They began using chequered flags to identify themselves. In some countries, the check pattern has become a symbol of the police. Known as "Sillitoe Tartan", it was first used in Glasgow in the 1930s and was inspired by a pattern worn by some
Police equipped with sirens and flashing light bars to aid in making others aware of police presence. Unmarked vehicles are used primarily for sting operations or apprehending criminals without alerting them to their presence. Some police forces use unmarked or minimally marked cars for traffic law enforcement, since drivers slow down at the sight of marked police vehicles and unmarked vehicles make it easier for officers to catch speeders and traffic violators. This practice is controversial, with for example, New York State banning this practice in 1996 on the grounds that it endangered motorists who might be pulled over by people