To support its digital collections, the Library of Congress uses a variety of standardized metadata and retrieval protocols. The Library is also involved in producing and maintaining standards for the use of other digital libraries. Some of the primary standards that focus on digital material are:

  • MARCXML and MODS – metadata to describe the content of a digital item
  • METS and MIX - metadata formats for media and environment of a digital item
  • PREMIS - metadata format supporting preservation activities for a digital item
  • SRU - protocol for search and retrieval in the digital environment

All of these standards are expressed using the XML schema language of the World Wide Web Consortium. These standards are maintained in the Network Development and MARC Standards Office of the Library of Congress. Learn more about metadata and retrieval standards

OAI-Harvestable Records

The Library of Congress makes descriptive records for some of its digitized collections available in the MODS and MARCXML formats via the Open Archives Initiative harvesting protocol, for integration into other services. Learn more about OAI harvestable records