The cataloging of microforms and other reproductions has been difficult throughout the history of cataloging codes, particularly due to the "multiple versions problem." The proposed new cataloging code, Resource Description and Access (RDA), seeks to clarify the relationship between reproductions and originals by applying the principles of Functional Requirements for Bibliographic Records (FRBR) to cataloging. While the use of FRBR principles does help to identify the relationships between works in the catalog, RDA as currently designed is challenging for the cataloger and includes many data that may prove to be difficult for catalog users to understand.