The complexity of the issues discussed in connection with the changing the trust fund by-laws reflects, at first, a certain helplessness when it comes to determining the place of the trust fund in Czech private law, understanding the ideological concept that the Czech legislator has chosen for the trust fund, and defining the relationship of the trust fund to other private law institutes. When searching for answers to any questions related to the degree of dispositiveness of the legal regulation, which is in principle intended as a regulation of a mandatory nature, it is therefore first necessary to identify the conceptual features and constitutive assumptions of the trust fund, which describe its uniqueness and which must remain its basic interpretive starting point.