The paper by E.F. Codd explores the extension of the relational model to capture more meaning in formatted databases. The primary goals are to identify meaningful units of data, both atomic and molecular, to enhance database design and improve the system's intelligence. The relational model, which was developed to abstract storage representation details, is extended to support these new semantics through new rules for insertion, update, and deletion, as well as new algebraic operators. The paper introduces a classification scheme for entities, properties, and associations, and discusses extensions to the relational model to reflect this classification. These extensions aim to support atomic and molecular semantics, including abstraction by generalization and Cartesian aggregation. The extended model is intended for database designers and sophisticated users. The paper also reviews the relational model, including its structures, algebra, and extensions for null values, and discusses the relationship between the relational model and predicate logic. It introduces the concept of entity domains and surrogates for unique and permanent identification of entities, and defines entity types, their properties, and associations. The paper concludes with a detailed explanation of how these concepts are implemented in the RM/T system, which aims to provide a more comprehensive and intelligent data model.The paper by E.F. Codd explores the extension of the relational model to capture more meaning in formatted databases. The primary goals are to identify meaningful units of data, both atomic and molecular, to enhance database design and improve the system's intelligence. The relational model, which was developed to abstract storage representation details, is extended to support these new semantics through new rules for insertion, update, and deletion, as well as new algebraic operators. The paper introduces a classification scheme for entities, properties, and associations, and discusses extensions to the relational model to reflect this classification. These extensions aim to support atomic and molecular semantics, including abstraction by generalization and Cartesian aggregation. The extended model is intended for database designers and sophisticated users. The paper also reviews the relational model, including its structures, algebra, and extensions for null values, and discusses the relationship between the relational model and predicate logic. It introduces the concept of entity domains and surrogates for unique and permanent identification of entities, and defines entity types, their properties, and associations. The paper concludes with a detailed explanation of how these concepts are implemented in the RM/T system, which aims to provide a more comprehensive and intelligent data model.