ISO/IEC 11179-2:2005 restates and elaborates on the procedures and techniques of ISO/IEC 11179-3:2003 for registering classification schemes and classifying administered items in a metadata registry (MDR). All types of administered items can be classified, including object classes, properties, representations, value domains, and data element concepts, as well as data elements themselves. ISO/IEC 11179-2:2005 develops a set of principles, methods, and procedures for specifying what is needed (at a minimum) to document the association between the various types of administered items and one or more classification schemes. This includes the names, definitions, and other aspects of the classification scheme and its contents. These can be captured through the use of a set of attributes. Particular attributes are specified in ISO/IEC 11179-2:2005, along with a structure for the contents of these attributes. Users may extend the set of attributes as necessary. Additional information may accompany a taxonomy or ontology; for example, to provide a suggested set of qualifiers that could be applied to the object class, property, or representation taxa to more fully qualify the classification of the particular administered item. ISO/IEC 11179-2:2005 summarizes the basic attributes and model specified in ISO/IEC 11179-3:2003.