Metadata Registries International Standard ISO/IEC 11179-1: 2015: Information Technology – Metadata Registries (MDR) – Part 1: Framework (see References) defines a framework for data semantics that is in practice used in connection with relational databases, but in theory could be applied more widely. In this framework, data encodes information about real-world objects and their properties. A data element is a unit of data that is considered in context to be indivisible. It is a logical specification to which a data value can conform, and that states what a conforming data value means. The meaning of a data element value is a combination of an object class and a property, such as person and name. A data element also has a value domain – its set of permissible values. When ISO/IEC 11179 is applied to a relational database, each table represents an object class, each column represents a data element, and each row represents an object and contains the values of the column data elements for that object. Usually, the table names and column names suggest the meaning of the data in a relational database. Formal documentation can describe the meaning more rigorously. Such documentation is a kind of metadata. ISO/IEC 11179 documents the standardization and registration of metadata to make data understandable and shareable.