 Many publications added the letter B after the P of its name to indicate its engine type, but this variation was never officially sanctioned by Ferrari which simply called it the 1971 312P.After boycotting sports car racing in 1968 to protest a rule change that also banned their 4-litre 330 P4, Ferrari built a 3000cc prototype in 1969, the "312 P".It was hardly more than a 3-litre F1 Ferrari 312 with open "Barchetta", and later the closed top "Berlinetta".