An arbitration clause contained in a specification document that is not expressly referenced in the main agreement maintains its effectiveness when it is attached to the resolution to which the agreement refers and is signed by both parties, thereby forming an integral part of the contractual framework.
The existence of an arbitration clause results in the ordinary court lacking jurisdiction (potestas iudicandi) and leads to the annulment of the payment order issued without proper jurisdiction, with referral of the parties to the competent arbitral tribunal pursuant to articles 809 et seq. of the Code of Civil Procedure.
In the absence of express contrary intention, an arbitration clause must be interpreted as conferring arbitral jurisdiction over all disputes relating to claims having their causa petendi in the contract to which said clause is attached.