Controlled Vocabularies are one of the semantic glues that binds open access repositories and scholarly communication infrastructures together. They offer great benefit to the community, because they ensure interoperability between repositories and repository content, and facilitate greater discovery, tracking and re-use of research materials. Faced with recurring issues in repository metadata the workshop will discuss the need of an agreed set of controlled vocabularies in bibliographic metadata. Examples include vocabularies on resource types, access rights, version and date types. They are being developed through the use of semantic products and standards and are the work of the COAR Interest Group on "Controlled Vocabularies for Repository Assets", established in 2014.