The paper discusses the application of Resource Description and Access (RDA), the emerging successor to the Anglo-American Cataloguing Rules, as a content standard for metadata encoded in UNIMARC. RDA is designed for international application in a digital environment, and is not aligned with any specific bibliographic record encoding format, although work is ongoing to develop its application to MARC21 and Dublin Core formats. The paper also discusses the implications of making components of RDA and associated models such as Functional Requirements for Bibliographic Records (FRBR) and Functional Requirements for Authority Data (FRAD) compatible with the Semantic Web. [ABSTRACT FROM AUTHOR].