The obligation of specific written approval of the arbitration clause under art. 1341 co. 2 cod. civ. presupposes the concurrent existence of two requirements: the unilateral drafting of the contractual terms by one of the contracting parties and the intended use of the contractual scheme to govern an indefinite series of relationships. The mere unilateral drafting is in itself insufficient to justify the application of arts. 1341 and 1342 cod. civ.
The fact that contracts are directed towards the completion of a specific work excludes the classification of the relevant contractual forms as general conditions of contract under art. 1341 cod. civ., inasmuch as the requirement that the scheme be drafted to govern an indefinite series of relationships is lacking, even where the principal has used standardised forms to formalise the relationships with the various suppliers.