The reserve of the title until the full payment of the price (Pactum reservati domini donec praetium solvitur) under the civil and then commercial sale contract had a vertiginous development in the 19th and 20th centuries. As it was not expressly regulated in the Civil Code or the Commercial Code, a wide range of solutions had been released over time – from challenging the validity of this clause by jurisprudence and doctrine, t...