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Digital Projects Toolkit: Metadata Guidelines

Metadata Guidelines/ Standards

Metadata Guidelines/ Standards
  • Metadata guidelines and supplements from the ND State Library
  • Examples of metadata guidelines from regional digital libraries
  • Examples of metadata standards

Metadata Guidelines

Metadata Standards

Metadata Standards: Overview

There are several metadata standards in use today. Metadata creators come from different fields. They have different approaches and needs when it comes to metadata. They create and collect different types of information for their varied collections. Therefore, there is no single standard that can easily satisfy the needs of the many different types of metadata creators. Each standard serves a certain purpose and audience. Below is a list of a few widely-used metadata standards. Each standards is explained in more detail on the tabs in this section.

  • Dublin Core
  • EAD (Encoded Archival Description)
  • MARC (MAchine Readable Cataloging)
  • MODS (Metadata Object Description Schema)
  • PBCore

Also included in this section is information on metadata "Crosswalks," which are guides that help adapt of translate one schema to another.

Dublin Core

According to the Western States Dublin Core Metadata Best Practices document (version 2.1.1, 2006), Dublin Core is "an internationally recognized metadata standard composed of fifteen basic elements, or descriptive categories, used to describe a variety of digital resources."

The fifteen "core" elements include: Contributor, Coverage, Creator, Date, Description, Format, Identifier, Language, Publisher, Relation, Rights, Source, Subject, Title, and Type.

Since its inception at a meeting in Dublin, Ohio, during the 1990s, Dublin Core has grown to be one of the most used metadata schemas. It serves as the basis of the metadata guidelines of the North Dakota State Library.

Element Description Additional Resources/ Schema
Contributor An entity responsible for making contributions to the resource.
Coverage The spatial or temporal topic of the resource, spatial applicability of the resource, or jurisdiction under which the resource is relevant.
Creator An entity primarily responsible for making the resource.
Date A point or period of time associated with an event in the lifecycle of the resource.
Description An account of the resource.  
Format The file format, physical medium, or dimensions of the resource.

An unambiguous reference to the resource within a given context..

Language A language of the resource.
Publisher An entity responsible for making the resource available.
Relation A related resource.  
Rights Information about rights held in and over the resource.
Source A related resource from which the described resource is derived.  
Subject The topic of the resource.
Title A name given to the resource.  
Type The nature or genre of the resource.



EAD (Encoded Archival Description) is "a standard for encoding descriptions of archival resources in XML so that the descriptions can be exchanged, modified, and rendered by computers" (Society of American Archivists). EAD is managed by the Society of American Archivists and the Library of Congress. The latest version is EAD3.



MARC stands for MAchine Readable Cataloging. In order for computers to easily use the bibliographic records added to online catalogs, they must be coded in a special computerized format. MARC is a format that a lot of libraries use. For example, instead of having a field called "title," title information is coded into a computerized language that uses 245 to house the information (Cataloging Resources: Glossary).

The "MARC record structure contains ten sets of fields, associated with 3-digit numbers called tags. Some fields are further defined by indicators and subfield codes" (University of Texas Libraries).

Components of a MARC Record (courtesy of University of Texas Libraries)

Tag Description
0XX Control information, numbers, and codes
1XX Main entries related to personal and corporate names
2XX Titles, edition, imprint information
3XX Physical description
4XX Series statements
5XX Notes
6XX Subject access entries
7XX Added entries other than subjects or series
8XX Series added entries and holdings information
9XX Fields for locally-defined use



MODS (Metadata Object Description Schema) is "a schema for a bibliographic element set that may be used for a variety of purposes, and particularly for library applications. The standard is maintained by the Network Development and MARC Standards Office of the Library of Congress with input from users" (MODS - Library of Congress).

MODS is "an XML schema with MARC-like semantics. MODS was developed by the Library of Congress out of the need for something easier to learn than MARC and richer than Dublin Core for describing complex digital objects... MODS is 'friendly' because it uses language-based tags rather than the numeric codes (e.g. 250) traditional to MARC. There are 20 top-level MODS elements, many of which contain subelements for granular description" (University of Texas Libraries).

The 20 top-level MODS elements include: Abstract, Access Condition, Classification, Extension, Genre, Identifier, Language, Location, Name, Note, Origin Info, Part, Physical Description, Record Info, Related Item, Subject, Table of Contents, Target Audience, Title Info, and Type of Resource.

Element Description
Abstract A summary of the content of the resource.
Access Condition Information about restrictions imposed on access to a resource.
Classification A designation applied to a resource that indicates the subject by applying a formal system of coding and organizing resources according to subject areas.
Extension Provides additional information not covered by MODS.
Genre A term or terms that designate a category characterizing a particular style, form, or content, such as artistic, musical, literary composition, etc.
Identifier Contains a unique standard number or code that distinctively identifies a resource.
Language A designation of the language in which the content of a resource is expressed.
Location Identifies the institution or repository holding the resource, the physical location of the resource, and/or the electronic location in the form of the digital resource in the form of a URL.
Name The name of a person, organization, or event (conference, meeting, etc.) associated in some way with the resource.
Note General textual information relating to a resource.
Origin Info Information about the origin of the resource, including place of origin or publication, publisher/originator, and dates associated with the resource.
Part A part of a resource.
Physical Description Describes the physical characteristics of the resource.
Record Info Information about the record.
Related Item Information that identifies other resources related to the one being described.
Subject A term or phrase representing the primary topic(s) on which a work is focused.
Table of Contents A table of contents for the resource.
Target Audience A description of the intellectual level of the audience for which the resource is intended.
Title Info A word, phrase, character, or group of characters, normally appearing in a resource, that names it or the work contained in it.
Type of Resource A term that specifies the characteristics and general type of content of the resource.



PBCore (Public Broadcasting Metadata Dictionary) is a metadata standard that is intended for sound and videos. The PBCore website says it "is a cataloging standard for the description of audiovisual content, a data sharing tool, and much more... The PBCore standard is composed of elements, attributes, and controlled vocabularies that make up its powerful descriptive system, or schema."

The key functions of PBCore are:

  • Guideline for cataloging or describing audiovisual content (as a content standard)
  • Model for building custom databases/applications
  • Guideline for identifying a set of vocabularies for fields describing audiovisual assets
  • Data model for a configurable collection management system (Omeka, Collective Access, etc.)
  • Exchange (import or export) mechanism between applications
  • Guideline for creating inventory spreadsheets



According to the University of Texas Libraries, metadata "crosswalks translate elements and values from one schema to those of another. Crosswalks facilitate interoperability between different metadata schemas and serve as the a base for metadata harvesting and record exchange."

Below is a list of crosswalks that have been developed (many by the Library of Congress) between common metadata standards.

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Many of these resources and programs are funded under the provisions of the Library Services and Technology Act from the Institute of Museum and Library Services.