Almost everybody knows that the black and white checked flag is used across the world of auto racing to signal the end of the race, when this flag is waved the required distance of the entire race has been reached by the lead driver and signals racing ends at the completion of the current lap. A number of flags are also used throughout the world to signal the same warnings to drivers, including the use of a yellow caution flag to signal drivers should be prepared for problems on the course ahead. The yellow flag is used across the world to warn drivers they should slow down and not overtake while this caution flag is in place. A red flag also carries the same meaning no matter which governing body is organizing and in control of the race, this flag means the race has been suspended and drivers should stop racing immediately no matter what their position on the track is.
Similar flags are also used across the world to inform drivers they are under investigation for an incident or have completed an act that has concerned race officials. A black flag is commonly used to inform drivers that they are being investigated and should be prepared to be ejected from a race or serve a stop go time penalty.
Similar flags are used in many different racing championships with slight differences, such as the blue flag in Formula 1 signaling a car is about to be lapped by a faster car and should yield track position. In the US, this flag has been adapted to a blue flag with orange stripe, which carries the same about to be overtaken warning. In Formula 1 racing a black flag featuring an orange disk is usually shown to a driver with a car fault that could endanger themselves and their fellow drivers, a similar flag is not available under US flag rules.
A white flag is used all around the world, however the US white flag has a different meaning to the rest of the world. In Formula 1 racing and championships governed by world bodies the white flag warns drivers they are about to enter a part of the course populated by slower cars. In the US, the white flag is used to warn the lead driver they are entering the final lap of the race.