Scope note: This class comprises agents who create the bibliographic description of publications and perform the authority control associated with such descriptions, for the description of copies of such publications actually held by libraries, and for the description of unique documents (manuscripts, objects…) held by libraries. The activity of creating such descriptions implies that one has to make decisions (as to the uniform title for a work, as to whether an arrangement still belongs to the same work or is definitely a new work, etc.). Since such decisions always are debatable and different agencies can make different decisions about the same real-world entities, it is important to document which agency made which decision. Examples: - The National Library of France, identified in bibliographic and authority records by the code ‘FRBNF’ at the beginning of INTERMARC field 001 - The National Library of Portugal, identified in bibliographic and authority records by the code ‘PTBNP’ at the beginning of UNIMARC field 001. - The Beinecke Rare Book and Manuscript Library, Yale University, identified in EAC files through the following elements: US-CtY-BR Beinecke Rare Book and Manuscript Library, Yale University .