This paper presents a model for non interpreted structures of logical systems, i.e., structures in which neither the type of transformations nor the contents of informations are specified. Systems structures are modelled by a set of Primitive Functional Entities (PFE), while informations are represented by dynamic entities called Information Flow Entity (IFE). To compensate the role of information contents, two subjectivity attributes are associated with each IFE. An application example is given to show how the above concepts are used.