A review of metadata: a survey of current resource description formats
Work Package 3 of Telematics for Research project DESIRE (RE 1004)
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Encoding Archival Description (EAD)

Environment of use


EAD consists of an SGML DTD, a Tag Library, Guidelines for its use, and examples. The Library of Congress Network Development/MARC Standards Office acts as the maintenance agency and the Society of American Archivists is the owner of the emerging standard, and is responsible through a committee representing the archival community for ongoing oversight and development.

(Note: at the time of writing the Beta EAD DTD and Tag Library are available at the Library of Congress site: <URL:ftp://ftp.loc.gov/pub/ead/> or from the current EAD web site at Berkeley: <URL:ftp://library.berkeley.edu/pub/sgml/ead/>).

Constituency of use

The EAD has been developed for use with archives and manuscripts collections. It was motivated by a desire to provide an enduring standard for machine representation of archival description and to facilitate uniform network access to archive and manuscript library collections. While MARC records provide summary description and access, EAD is intended to provide detailed description and access. The two descriptive methods are intended to be complementary, with MARC records providing summary representation of collections in bibliographic databases that lead to the detailed EAD-based finding aids (i.e. detailed catalogues). EAD provides a structure for describing archive and library finding aids and is primarily intended for inventories and registers. It accommodates registers and inventories of any length describing the full range of archival holdings in various media.

(Note: US usage is 'finding aids', while UK usage calls similar descriptions 'detailed catalogues'.)

Ease of creation

The EAD provides an apparatus for full, hierarchical description and is designed for use by those with a knowledge of collections and archival practice.

Progress towards international standardisation

EAD is not an international standard, though is receiving international interest. The Library of Congress Network Development/MARC Standards Office acts as a maintenance agency for EAD. The Society of American Archivists will retain ongoing oversight for development. The Beta version of EAD and an electronic version of the guidelines are scheduled to appear in late Summer or Autumn of 1996. Discussions concerning the internationalisation of EAD and compliance with International Standard Archival Description (ISAD(G)) are underway.

Other comments

EAD recognises that the TEI guidelines and USMARC are related and complementary. The data model includes a finding aid header which is based on, and thus similar to, the TEI header. (Encoding standard for electronic finding aids: a report by the Bentley Team for Encoded Archival Description Development. n.d.).

Format issues


Basic descriptive elements

An overview of high-level descriptive elements is given here. Lower-level descriptive elements and some other elements are not listed. This list reflects the standing of the DTD as of August 1996, and may be changed in later versions.

          <archdesc> (Archival Description)
               <did> (Descriptive Identification)
               <odd> (Other Descriptive Data)
               <dsc> (Description of Subordinate Components)
                    <c> (Component)
          <add> (Adjunct to Descriptive Data)

Subject description

There is a variety of elements including <subject>, but <scopecontent> is also important.


The finding aid itself has an <eadid> element for uniform representation of a unique identification of the archival collection. In addition, the <unitid> is to be used for unique identification of the archival collection. Emerging IAAD(G) naming/ID conventions need to be reconciled and developed in light of international Internet standards. Finally, the element <dao> or Digital Archival Object for original digital and digital representations of archival material will use SGML formal public indentifiers that will be mapped, using SGML standards, and depending upon the method chosen, to emerging Internet standards: PURL, CNRI handles, and when available other URIs.

(Note: Berkeley and Library of Congress are experimenting with respect to pointing. LC seems to be going with CNRI handles, Berkeley with PURLs.)

Resource format and technical characteristics

The <physdesc> element is used to describe the physical characteristics of the object being described in the <ead> (e.g. a letter written by Mark Twain).

Where a digital representation of the file exists, physical characteristics of the representation (file size, format, information documenting the capture process, etc) will reside in the header of the digital representation file, or if it is maintained separately, in a separate metadata format and syntax (e.g. a digital representation of a letter written by Mark Twain; with separate physical characteristics and capture information on each page-image).

Host administrative details

DTD has elements for repository/authoritative agency. <eadid> has an attribute for explicit representation of authoritative/host institution when this is not in a machine-parsable form in the data in the element itself.

Administrative metadata

Carried in the <eadheader> subelements <filedesc> and <profiledesc>. The element and subelements are based on the TEI header, though simpler.



Terms of availability/copyright

<accessrestrict> and <userestrict>

Designation and Encoding

The EAD has been implemented as an SGML DTD.

Multi-lingual issues

The DTD invokes ISO standard entity sets. Full details from the LC Network Development/MARC standards Office. Usage is compatible with mapping to Unicode when there is sufficient software support for it.


Less full than MARC and TEI by design, but still a relatively rich format.

Protocol issues

EAD does not prescribe any search or transport protocols.


There are major projects at the Library of Congress and the following US universities: Berkeley, Yale, Harvard, Duke, Stanford, and Virginia. There are also several projects initiated by the National Endowment for the Humanities and also some other projects.

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Last update: 10-Jun-1998