SAA
LCEncoded Archival Description (EAD) is the predominant XML standard for encoding archival finding aids -- the detailed inventories and guides that describe the contents and organization of archival collections. Maintained jointly by the Society of American Archivists (SAA) and the Library of Congress, EAD has been fundamental to making archival collections discoverable online since the late 1990s. The current version, EAD3, was released in 2015 and continues to be updated, with version 1.1.1 as the latest release.
Background
EAD originated from a project at the University of California, Berkeley, led by Daniel Pitti beginning in 1993. The goal was to create a machine-readable encoding for finding aids that could preserve their hierarchical structure -- the nested arrangement of fonds, series, sub-series, files, and items that reflects how archival materials are organized according to the principle of provenance. The first version of the EAD DTD was released in 1998, and a substantially revised version, EAD 2002, became the standard adopted by archives worldwide.
The Library of Congress serves as the maintenance agency, hosting the official EAD site and distributing the schemas. The Society of American Archivists, through its Technical Subcommittee on Encoded Archival Standards (TS-EAS), is responsible for intellectual maintenance and development of the standard.
Purpose and Scope
EAD encodes the content and structure of archival finding aids. A finding aid typically includes administrative and biographical/historical information about the creator of the records, a scope and content note describing the collection as a whole, and a hierarchical container list that describes the arrangement of materials at varying levels of specificity. EAD maps these components into a structured XML format that can be rendered for display on the web, ingested into discovery systems, or exchanged between repositories.
EAD is used by archives of all types -- university and research archives, government archives, corporate archives, manuscript repositories, and special collections within libraries. It is the standard expected by major union catalog systems including ArchiveGrid and the Archives Portal Europe.
Key Elements
EAD3 organizes its elements around the structure of a finding aid:
| Element | Description | Level |
|---|---|---|
<control> |
Administrative metadata about the finding aid itself | Top-level |
<archdesc> |
The archival description proper | Top-level |
<did> |
Descriptive identification (title, dates, extent, repository) | Nested |
<scopecontent> |
Scope and content note | Component |
<bioghist> |
Biographical or historical note about the creator | Component |
<arrangement> |
Information about the organization of materials | Component |
<accessrestrict> |
Access restrictions | Component |
<c> / <c01>-<c12> |
Component levels representing hierarchical arrangement | Nested/recursive |
<daoset> / <dao> |
Links to digital archival objects | Nested |
Serializations and Technical Formats
EAD is defined as an XML schema (XSD) and DTD. EAD3 schemas and the DTD are available from the Library of Congress website and from the SAA-SDT GitHub repository. The schema supports validation of EAD-encoded finding aids. While EAD is XML-based, it is not an RDF vocabulary; it follows a document-oriented rather than graph-oriented approach to encoding.
EAD 2002 schemas and DTDs remain available for legacy implementations, though this version is deprecated and no longer actively developed.
Governance and Maintenance
EAD is governed by the Technical Subcommittee on Encoded Archival Standards (TS-EAS) of the Society of American Archivists. The Library of Congress serves as the maintenance agency, responsible for hosting documentation and distributing schemas. Development work is conducted openly on GitHub, where issues can be reported and feature requests submitted. The EAD listserv, hosted by the Library of Congress, provides a community discussion channel for implementers and developers.
TS-EAS has issued a Statement on Standards Alignment that addresses the relationship between EAD and other encoded archival standards including EAC-CPF (Encoded Archival Context -- Corporate Bodies, Persons, and Families).
Notable Implementations
EAD is implemented by thousands of archives worldwide. Major aggregation services that harvest EAD finding aids include ArchiveGrid (OCLC), the Archives Portal Europe, and numerous state and regional archival portals in the United States. Library discovery systems such as ArchivesSpace, Archon, and AtoM produce and consume EAD-encoded finding aids. The standard is also supported by tools like the Oxygen XML editor, which can validate EAD documents against the schema.
The EAD3 Starter Kit on GitHub provides templates and examples for institutions beginning to implement the current version of the standard.
Related Standards
- EAC-CPF -- Encoded Archival Context for Corporate Bodies, Persons, and Families, a companion standard for encoding authority records for the creators of archival materials.
- DACS -- Describing Archives: A Content Standard, which provides the content rules that complement EAD's structural encoding.
- ISAD(G) -- The International Standard Archival Description (General), the international descriptive standard that influenced EAD's structure.
- MARC 21 -- The library cataloging format, for which crosswalks to and from EAD exist.