Metadata-related standards are formal documents that establish uniform criteria, methods, processes, and practices for documentation. They serve as guidelines for designing, creating, and implementing data structures, data values, and data content, ensuring the efficient and consistent use of data. Metadata standards in the context of research data and cultural heritage documentation can be grouped into three categories based on the purpose for which they were developed: standards for data content, for data structures (element sets and schemas), and for data values (vocabularies).