The number of cars entered by one team into a single race was not strictly limited in the 1950s and early 1960s. Since the season teams were generally allowed to enter only two regular cars, with the third car reserved for an occasional driver. This rule was further promoted since the season by the assignment of the permanent racing numbers to each team in pairs, with the third car having the racing number out of the pair. Entering more than three cars was exceptionally tolerated, most notably regarding the BRM team in the and seasons. However, many teams during this period entered only two cars, e.g. Ferrari have entered no more than two cars (with one exception at the 1976 Italian Grand Prix in connection with Lauda's comeback) every season since . Since the season the FIA have required that teams enter no more than two cars for a race. Team's nationality Unlike drivers who are required to compete in the FIA Formula One World Championship under the nationality of their passport, the FIA's International Sporting Code states that teams competing in the FIA Formula One World Championship shall compete under the nationality of their parent National Automobile Club that issued their FIA racing licence. On the basis of this regulation, despite the fact that most current teams are based in the UK, this country is officially represented in Formula One only by teams holding a racing licence issued by the British National Sporting Authority. Teams take the nationality of their parent National Automobile Club that issued their licence for the period of validity of that licence and the change of the nationality is allowed. Several teams changed their nationality during their competition in Formula One, some of them even twice (e.g. Shadow in from American to British, Benetton in from British to Italian, Red Bull in from British to Austrian, Renault in from French to British and in back to French). Benetton is the only team to have achieved victories while racing under two different nationalities. Before the arrival of sponsorship liveries in the season team's nationality determined the colour of a car entered by the team; thus, Italian teams' cars were rosso corsa red, French were bleu de France blue, and British (with several exceptions, such as Rob Walker, Brabham and McLaren) were British racing green. Since the licence is given to a team and not to a