According to the Dublin Core Metadata Initiative, an Application Profile is the "assemblage of metadata elements selected from one or more metadata schemas and combined in a compound schema". The European Library has developed two Application Profiles, based on Dublin Core elements; one for objects and one for collection descriptions.

Terms used in the different Application Profiles are gathered into The Metadata Registry. The European Library Metadata Registry contains all the terms in use in the portal, some that have been proposed for inclusion and some that have been considered and rejected.

Partners need to run the same searches in the fields (Any, Title, Author, Subject, Language, ISBN, ISSN) both in The European Library and in their local collection interface. These searches should be done in a partner's own languages. The aim of this test is to make sure that the same number of results are received from The European Library portal as in the local interface: Testing metadata. Partners can also consult a test collection with 1 record containing all fields described in The European Library Application Profile: http://search.theeuropeanlibrary.org/portal/en/search/collections/test/test.query. Partners should obtain this result :