The Dublin Core

One of my favorite classes over the course of my graduate education was Organization of Information (LI804XR). The finer details of cataloging, access points, metadata, and other concepts surrounding the ways we treat information were examined. One assignment involved explaining a metadata schema, which represented an opportunity for me to explore the Dublin Core metadata schema.**

The Dublin Core is a metadata schema which, over the last twenty-five years, has been one of the most widely accepted standards for the description of both digital and physical resources on the internet. The "Dublin" half of Dublin Core comes from the city in Ohio where a “Metadata Workshop” hosted by the OCLC (Online Computer Library Center) and the National Center for Supercomputing Applications (NCSA) was held in 1995. The stated goal of the m eeting involved “promoting a consensus on a core set of metadata elements to describe networked resources,” and so it was at this workshop that the ba sic core elements—thirteen initially; fifteen eventually—were introduced (Weibel, 1995). “Core” in this case refers to the fifteen descriptive metada ta elements representing its foundation—that is, fifteen core properties or terms through which a given resource can be described.

This set of fiftee n metadata elements is often called the Dublin Core Metadata Element Set (DCMES) or alternately, Simple Dublin Core (usually to distinguish it from th e more detailed and iterative Qualified Dublin Core). Each metadata element of the DCMES is defined on the official website of the Dublin Core Metadat a Initiative (DCMI) as follows:

It is, of course, no coincidence that these fifteen elements are arranged alphabetically. One could reasonably assume that the decision to do so effectively conveys that there is in fact no preferred or recommended order of arrangement for these elements when either composing or presenting a metadata record with the Dublin Core schema.

Moreover, each Dublin Core element is technically optional; depending on the resource in question, a few or perhaps several elements might be inapplicable—a sculpture would likely not have any relevant information to ascribe to the Publisher element, for instance—or certain data simply may be unavailable.

Dublin Core largely adheres to the Resource Description Framework (RDF) data model. This aspect lends itself to the Dublin Core schema being relatively interoperable and thus more readily adopted and standardized by various fields.

Perhaps most noteworthy in terms of Dublin Core's value across and between various fields and disciplines is its extended and expanded element set, originally known as Qualified Dublin Core but since reestablished as the DCMI Metadata Terms. The DCMI Metadata Terms includes the original foundational core of fifteen descriptive elements (or “terms”) as well as fifty-five additional terms meant to augment, extend, refine, or provide further detail than the DCMES (Simple Dublin Core).

Most of Qualified Dublin Core's descriptive terms are intended to offer a refinement of detail or an improvement upon the information expressed through Simple Dublin Core. With regard to interoperability, the DCMI Metadata Terms are structured in such a way that, should an application be incompatible with any of Qualified Dublin Core's expanded descriptive terms, those expanded terms are ignored in favor of the corresponding Simple Dublin Core term.

In addition to these expanded descriptive terms are several groups of elements that function as classes, vocabulary encoding schemes, syntax encoding schemes, as well as twelve extensions of the “Type” core element. Among the nine vocabulary encoding schemes utilized by the DCMI Metadata Terms are the Library of Congress Subject Headings (LCSH), the Internet Assigned Numbers Authority (IMT), and the Medical Subject Headings (MeSH).

ISO 3166, which controls how the names of countries are represented, and W3C-DTF, which controls how dates and times are formatted and displayed, are two of several syntax encoding schemes used by DCMI Metadata Terms.

These vocabulary and syntax encoding schemes work together to ensure a controlled vocabulary, which itself contributes to a robust level of consistency and standardization across geographic regions, disciplines, platforms, and users.

A typical metadata record utilizing the Dublin Core metadata schema might be representative of an image, a sound file, a video file, or some other such resource one might find in any given corner of the internet or on a library's online database. That said, the Dublin Core metadata schema isn't limited to describing electronic resources—it's also widely used to describe anything from sculptures, paintings, or video cassettes to photo exhibits, hard copies of symphonies on sheet music, or even past musical performances and festivals. A Dublin Core metadata record might be presented in its entirety or partially, depending on the provider of the discovery tool, database, etc., and sometimes a metadata record may not incorporate all fifteen core elements. As mentioned before, sometimes metadata surrogate records are limited by the very nature of the resource they describe—a sound file doesn't have physical dimensions, after all—and sometimes they are limited by a lack of available data, as in many historical audio and film files. A full metadata record is often presented in a table format, as below, or the information might also be transposed to HTML or XML as well:


<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"
<head profile="">
<link rel="schema.DC" href="">
<link rel="schema.DCTERMS" href="">
<meta name="DC.Title" content="Forest">
<meta name="DC.Creator" content="Winston, George">
<meta name="DC.Subject" content="Solo piano">
<meta name="DC.Description" content="Solo piano recording">
<meta name="DC.Publisher" content="Dancing Cat Records">
<meta name="DCTERMS.DateCopyrighted" scheme="DCTERMS.W3CTDF" content="1994">
<meta name="DC.Type" scheme="DCTERMS.DCMIType" content="Sound">
<meta name="DC.Format" scheme="DCTERMS.IMT" content="Audio 
CD"> <meta name="DC.Identifier" content="ISBN13:0618321527726"> 
<meta name="DC.Rights" content="Copyright 1994">
<meta name="DCTERMS.RightsHolder" content="Wyndham Hill">
<meta name="DC.Language" scheme="DCTERMS.ISO639-2" content="English">

As seen above in the HTML representation of this metadata record, some of these terms are from Qualified Dublin Core. “DateCopyrighted” is syntax-controlled by the W3CTDF syntax encoding scheme, while “Language” is being controlled by the ISO639-2 syntax encoding scheme. “Type,” as was previously mentioned, is governed by twelve different sub-terms, and “Sound” represents the appropriate value in this case. Also included in the HTML are reference links to the DCMI source pages.


DCMI metadata terms. DCMI. (n.d.). Retrieved October 10, 2021, from

Dublin Core. DCMI. (n.d.). Retrieved October 10, 2021, from

Weibel, S. (1995, July 1). Metadata: The Foundations of Resource Description. Retrieved October 9, 2021, from


Khadem-Rezaiyan, M., Rashidtorabi, Z., Youssefi, M., Zeinalipour, Z. (2018). The future of medical students; perspectives and expectations: a cross-sectional study in Mashhad University of Medical Sciences. Research & Development in Medical Education. 7 (1), 26-31.

Ullmann, C., & Zott, L. M. (Eds.). (2013). Medical technology. Detroit, MI: Greenhaven Press.

Kemppainen, S. (2018, June). Best Medical Careers For The Future. Best Medical Degrees. Retrieved from

Tags: dublin-core, schemas, NCSA

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