The requirement for specific written approval of arbitration clauses for regular arbitration pursuant to Article 1341, paragraph 2, of the Civil Code applies when such clause is inserted within general contract conditions, understood as those prepared to serve an indefinite series of relationships. Such requirement does not apply when the contract containing the arbitration clause cannot be qualified as an adhesion contract, being characterised by the presence of elements specifically referable to the contracting party and by a precisely described object, elements incompatible with a contractual scheme destined to govern an indefinite series of relationships with an indistinct plurality of subjects.