本文件通过描述分类方案的注册并使用它们对MDR中的注册项目进行分类，对ISO/IEC 11179-3进行了补充。任何元数据项都可以成为可分类的_项，以便对其进行分类，可以包括对象类、属性、表示、概念域、值域、数据元素概念和数据元素本身。 本文件未将特定的分类方案确定为卓越。对特定分类学方法和/或特定认识论的认可也超出了本文件的范围。这些问题由其他标准委员会解决，和/或倾向于针对特定的论述领域进行调整。MDR可以建立自己的分类方案，其他标准委员会正在开发或已经开发用于分类和/或本文件适用的特定技术和结构的规范性语言。 按照ISO/IEC 11179-6中的描述和规定，每个注册机构可以根据其认为合适的分类方案、结构和内容对可分类项目进行分类。在记录可分类项目的分类方面时，登记机关可以使用本文件中涵盖的原则、方法、程序和属性。

This document compliments ISO/IEC 11179-3 by describing registration of classification schemes and using them to classify registered items in an MDR. Any metadata item can be made a Classifiable_Item so it can be classified, which can include object classes, properties, representations, conceptual domains, value domains, data element concepts and data elements themselves. This document does not establish a particular classification scheme as pre-eminent. Sanction of a particular taxonomic approach and/or a particular epistemology is also beyond the scope of this document. These are addressed by other standards committees and/or tend to be tailored to a particular domain of discourse. The MDR can establish its own classification schemes, and other standards committees are developing or have developed normative languages for use in classification and/or particular techniques and structures that can be accommodated by this document. Each registration authority, as described and specified in ISO/IEC 11179-6, can classify classifiable items according to the classification schemes, structures and content that it deems appropriate. In documenting the classification aspects of classifiable items, the registration authority can use the principles, methods, procedures and attributes covered in this document.