The arbitration clause provided for by the by-laws of sports federations, referring to contractual arbitration (arbitrato irrituale) disputes of a purely pecuniary nature originating from sporting or associative activities between affiliated entities and registered members, applies where both the subjective element of the affiliation of the association and the registration of the natural persons, and the objective element of the purely pecuniary nature of the dispute, are present, the latter being satisfied irrespective of the contractual or tortious nature of the liability invoked, provided that the claim concerns the recovery of damages consequent upon allegedly unlawful conduct of the opposing party.