Subelement Working Draft

This report is a record of the efforts of the Subelement working group constituted following the Helsinki Dublin Core™ Metadata Workshop (DC-5) of October, 1997. The recommendations are provisional and can be expected to evolve in the light of further implementation experience.

Although simplicity remains one of the fundamental tenets of the Dublin Core™ metadata initiative, a significant body of the stakeholder community believes that the option to refine the semantics of the element set through the addition of qualifiers is essential to allow effective deployment of the Dublin Core™ for resource discovery. To address these shortcomings, the qualifiers SUBELEMENT, SCHEME and LANG were proposed at the 4th Dublin Core™ workshop in Canberra, Australia. These optional qualifiers, now known as the 'Canberra Qualifiers', are:

SUBELEMENT , which allows the refinement and clarification of an element's content, such as, for example, refining the definition of DATE into Date Created, Date Acquired, etc.

SCHEME , which allows an element's value to be identified as part of an existing classification system, coding scheme, glossary or thesaurus, such as the Dewey Decimal Classification for books or the Art & Architecture Thesaurus for cultural heritage.

LANG , which specifies the base language of an element's attribute values and text content; it is recommended that the values for this element are compliant with the scheme for creating language tags described by RFC 1766.

By optionally applying any or all of these qualifiers to the 15 elements of the Dublin Core, more detailed and semantically specific information about a resource can be encoded, thus assisting precision in the discovery and retrieval process for systems that support the use of these qualifiers. The Subelement working group spent most time addressing the first of these qualifiers, SUBELEMENT, although some attention was also devoted both to the other qualifiers and to issues considered generic to all three. This report details only the work on the SUBELEMENT qualifier.

Whilst complex applications of Dublin Core™ are likely to have differing requirements for specialist SUBELEMENTs, early implementers frequently identified a common requirement for certain key SUBELEMENTs. Rather than encourage proliferation of these common SUBELEMENTs, with each application employing slightly different nomenclature and semantics, the most commonly utilised SUBELEMENTs identified to date are gathered together below, and presented in a standardised form. As can be seen, most of the 15 elements remain unqualified.

TITLE
The Dublin Core™ TITLE element has the following subelements:

Alternative
Used for any titles other than the main title; including subtitle, translated title, series title, vernacular name, etc.

Main
Used where two or more titles are being recorded for the same resource in order to distinguish the main title from alternative titles.

CREATOR
The Dublin Core™ CREATOR element has the following subelements:

PersonalName
The name of an individual associated with the creation of the resource. The PersonalName subelement itself has the following subelement:

Address
An electronic or physical address for the individual in question. This could be an electronic mail address, web page URL, postal address, etc.

CorporateName
The name of an institution or corporation associated with the creation of the resource. The CorporateName subelement itself has the following subelement:

Address
An electronic or physical address for the institution or corporation in question. This could be an electronic mail address, web page URL, postal address, etc.

SUBJECT
No core SUBELEMENTs at present.

DESCRIPTION
No core SUBELEMENTs at present.

PUBLISHER The Dublin Core™ PUBLISHER element has the following subelements:

PersonalName
The name of an individual associated with the publication of the resource. The PersonalName subelement itself has the following subelement:

Address
An electronic or physical address for the individual in question. This could be an electronic mail address, web page URL, postal address, etc.

CorporateName
The name of an institution or corporation associated with the publication of the resource. The CorporateName subelement itself has the following subelement:

Address
An electronic or physical address for the institution or corporation in question. This could be an electronic mail address, web page URL, postal address, etc.

CONTRIBUTOR
The Dublin Core™ CONTRIBUTOR element has the following subelements:

PersonalName
The name of an individual associated with the resource. The PersonalName subelement itself has the following subelement:

Address
An electronic or physical address for the individual in question. This could be an electronic mail address, web page URL, postal address, etc.

CorporateName
The name of an institution or corporation associated with the resource. The CorporateName subelement itself has the following subelement:

Address
An electronic or physical address for the institution or corporation in question. This could be an electronic mail address, web page URL, postal address, etc.

DATE
The Dublin Core™ DATE element has the following subelements, which are discussed further in the report of the Date Working Group:

Created
Date of creation of the resource Issued Date of formal issuance (e.g., publication) of the resource.

Accepted
Date of acceptance (e.g., for a dissertation or treaty) of the resource. Available Date (often a range) that the resource will become or did become available.

Acquired
Date of acquistion or accession.

DataGathered
Date of sampling of the information in the resource. Valid Date (often a range) of validity of the resource.

TYPE
No core SUBELEMENTs at present.

FORMAT
No core SUBELEMENTs at present.

IDENTIFIER
No core SUBELEMENTs at present.

SOURCE
No core SUBELEMENTs at present.

LANGUAGE
No core SUBELEMENTs at present.

RELATION
The Dublin Core™ RELATION element has the following subelements, which are discussed further in the report of the Relation Working Group: Type Indicator

COVERAGE
The Dublin Core™ COVERAGE element has the following subelements, which are discussed further in the report of the Coverage Working Group:

PeriodName
The resource being described is from or related to a named historical period, referred to by this use of the element.

PlaceName
The resource being described is associated with a named place, identified by this use of the element.

x
The resource being described is associated with a spatial location which may be defined by the use of x, y, (and, possibly, z) co-ordinates. The x co-ordinate is given in this use of the element.

y
The resource being described is associated with a spatial location which may be defined by the use of x, y, (and, possibly, z) co-ordinates. The y co-ordinate is given in this use of the element.

z
The resource being described is associated with a spatial location which may be defined by the use of x, y, (and, possibly, z) co-ordinates. The z co-ordinate is given in this use of the element.

t
The resource being described is from or associated with an instance in time which may be given numerically.

Polygon
The resource being described may be located with respect to a shape, or polygon, defined in space as a series of x,y co-ordinate values.

Line
The resource being described may be located with respect to a line defined in space by a series of x,y co-ordinate values.

3d
The resource being described may be located with respect to a volume, or hull, defined in three dimensional space as a series of x,y,z co-ordinate values.

RIGHTS
No core SUBELEMENTs at present.