Semantic quirks about the concept of metadata are briefly probed. The reasons behind the conceptual drift are also reviewed. Regarding different formats of metadata, the rationale behind the creation of new formats, their characteristics in relation to MARC format, and problems and methods of conversion or integration of metadata are investigated as background study. RDF (Resource Description Framework) as an integration tool for different metadata standards and Metadata Registry as a candidate for the purpose are studied and the both are compared. It is concluded that two approaches are not mutually exclusive, rather they are complimentary.