Original: The traditional recipe, registered in 1982 by the Bolognese delegation of Accademia Italiana della Cucina, confines the ingredients to beef, pancetta, onions, tomato paste, meat broth, white wine, and milk or cream.
Simplified: In 1982, the Bolognese delegation of Accademia Italiana della Cucina said that the recipe may only contain beef, pancetta, onions, carrots, celery, tomato paste, meat broth, red wine, and (optionally) milk or cream.