An arbitration clause contained in condominium regulations or multi-ownership regulations unilaterally drafted by the builder-seller and referenced in a sale and purchase agreement concluded between a professional and a consumer constitutes an unfair term pursuant to Article 33, letter (t), of Legislative Decree No. 206 of 6 September 2005, when it creates a significant imbalance in the rights and obligations arising from the contract to the detriment of the consumer, indirectly affecting the contractual synallagma (reciprocal obligations) by imposing lasting limitations on the methods of access to judicial protection for the exercise of acquired rights, unless it results from specific acceptance or from genuine individual negotiation characterised by the requirements of seriousness, effectiveness and individuality.