Recent research in Design Theory and Methodology has sought to formalize the engineering design process without particular concern for the paradigm used to model design information. The authors propose that no correct formalization of the design process can be achieved without first formalizing the semantics of the information used in the process. To this end, the authors present a new theory meant to formalize the semantics of design information that is independent of its use in a design process. Using symbolic logic, the theory is presented as a set of axioms, and draws from the object orientation and hypertext paradigms. Design entities are modeled by formal units called objects, and are related by formal structures called links. Abstraction mechanisms relevant to design are formalized and the role of constraints is explored. The hybrid model is meant not only to aid in the study of the design process itself, but also to improve communications between designers, assist standardization of design specifications, and develop new, powerful software tools to aid the designer in his work.