Restates and elaborates on the procedures and techniques of ISO/IEC 11179-3:2003 for registering classification schemes and classifying administered items in an 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. This part 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 use of a set of attributes. Particular attributes are specified in this part, along with a structure for the contents of these attributes. Users may extend the set of attributes as necessary.