For the purpose of identifying the discipline applicable to arbitration, reference must be made to the date of subscription of the arbitral clause, Article 829 of the Code of Civil Procedure applying in the formulation preceding the modification introduced by Legislative Decree N. 40/2006 when the clause predates such reform.
An arbitration clause relating to the "interpretation and execution" of the contract may find application also in relationships deriving from assignment of credits and subrogation occurring by subsequent deed, provided that the substantive relationship remains referable to the original contract containing the clause.
In the pre-2006 reform discipline, Article 819-bis of the Code of Civil Procedure provided for suspension of arbitral proceedings only in the presence of a prejudicial question on the merits not capable of arbitration that had to be decided by a judge with res judicata effect, or in the case of loss of capacity of a party.
Violation of the principle of due process in arbitration subsists not in the presence of non-admission of evidential applications, but when there is lacking respect for the fundamental right of parties to speak and contradict on equal terms.
The claim of nullity of an arbitral award for non-observance of rules of law postulates explicit allegation of the erroneousness of the legal principle applied in relation to the elements ascertained by the arbitrators, and is not available in connection with the mere pleading of lacunae in investigation and reasoning.
In proceedings for challenge for nullity of an arbitral award the rule of specificity in the formulation of grounds applies, given its rescissory nature and the necessity to enable the judge and the opposing party to verify whether the challenges proposed correspond exactly to those formulable according to Article 829 of the Code of Civil Procedure.