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The Samvera Community has developed metadata recommendations, including mapping recommendations for objects currently defining metadata using XML. Fedora 5.x uses a set of internal properties (see http://fedora.info/definitions/v4/repository) and by supplies the following ontologies by default: Fedora Namespace Registry. It is possible to include and use any ontology that exists, although it is recommended to use ontologies that are shown to be currently active and well-maintained for longevity purposes.
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