In spite of popular myth, most modern "broncs" are not in fact wild horses, but are more commonly spoiled riding horses or horses bred specifically as bucking stock. Rough stock events also use at least two well-trained riding horses ridden by "pick up men" (or women), tasked with assisting fallen riders and helping successful riders get safely off the bucking animal. Several other events may be scheduled on a rodeo program depending upon the rodeo's governing association. Outside of competitive events, other activities are often associated with rodeos, particularly at local levels. A typical rodeo begins with a "Grand Entry", in which mounted riders, many carrying flags, including the American flag, state flags, banners representing sponsors, and others enter the arena at a gallop, circle once, come to the center of the arena and stop while the remaining participants enter. The grand entry is used to introduce some of the competitors, officials, and sponsors. It is capped by the presentation of the American flag, usually with a rendition of "The Star-Spangled Banner," and, depending on region, other ceremonies. If a rodeo queen is crowned, the contestants or winner and runners-up may also be presented. Variety acts, which may include musicians, trick riders or other entertainment may occur halfway through the rodeo at intermission. Some rodeos may also include novelty events, such as steer riding for preteens or "mutton busting" for small children. In some places, various types of novelty races or events such as wild cow milking are offered for adults. Such contests often are unregulated, with a higher risk of injury to human participants and poor treatment of animals than in traditionally-sanctioned events, particularly if consumption of alcoholic beverages by participants is permitted. Formal associations and detailed rules came late to rodeo. Until the mid-1930s, every rodeo was independent and selected its own events from among nearly one hundred different contests. Until World War I, there was little difference between rodeo and "charreada". Athletes from the US, Mexico and Canada competed freely in all three countries. Subsequently, "charreada" was formalized as an amateur team sport and the international competitions ceased. It remains popular in Mexico and Hispanic communities of the U.S. today. Numerous associations govern rodeo in the United States, each with slightly different rules and different events. The oldest and largest sanctioning body of professional rodeo is the Professional Rodeo Cowboys Association (PRCA) which governs about a third of all rodeos staged in the US annually.