In Association football (soccer), the referee shows a yellow card to indicate that a player has been officially warned because they have committed a foul or have wasted time. Originally in Rugby league and then later, also in Rugby Union, the referee shows a yellow card to indicate that a player has been sent to the sin bin. In cycle racing, the yellow jersey – or maillot jaune – is awarded to the leader in some stage races. The tradition was begun in the Tour de France where the sponsoring L'Auto newspaper (later L'Équipe) was printed on distinctive yellow newsprint. Transportation In some countries, taxicabs are commonly yellow. This practice began in Chicago, where taxi entrepreneur John D. Hertz painted his taxis yellow based on a University of Chicago study alleging that yellow is the color most easily seen at a distance. In Canada and the United States, school buses are almost uniformly painted a yellow color (often referred to as "school bus yellow") for purposes of visibility and safety, and British bus operators such as FirstGroup are attempting to introduce the concept there. "Caterpillar yellow" and "high-visibility yellow" are used for highway construction equipment. In the rules of the road, yellow (called "amber" in Britain) is a traffic light signal meaning "slow down", "caution", or "slow speed ahead". It is intermediate between green (go) and red (stop). In railway signaling, yellow is often the color for warning, slow down, such as with distant signals. Selective yellow is used in some automotive headlamps and fog lights to reduce the dazzling effects of rain, snow, and fog. Maritime signaling In International maritime signal flags a yellow flag denotes the letter "Q". It also means a ship asserts that it does not need to be quarantined. Idioms and expressions Yellow-belly is an American expression which means a coward. The term comes from the 19th century and the exact origin is unknown, but it may refer to the color of sickness, which means a person lacks strength and stamina. Yellow journalism is also an American term for news which present limited research to its findings. Yellow pages refers in various countries to directories of telephone numbers, arranged alphabetically by the type of business or service offered. The Yellow Peril was a term used in politics and popular fiction in the late 19th and early 20th century to describe the alleged economic and cultural