SKOS Core is a supporting RDF Vocabulary for describing concepts and concept schemes. (A 'concept scheme' is defined here as 'a description of a set of concepts, optionally including a description of relationships between those concepts'.) In general terms, the main function of SKOS Core is to support structured descriptions of conceptualisations, for the purpose of establishing common meaning within a community of people.
SKOS Core is also proposed as a standard framework for creating RDF descriptions of the more linguistically oriented types of knowledge organisation system, such as thesauri, subject heading schemes, terminologies, glossaries, classifications schemes, other controlled vocabulary types etc.
This section describes the status of this document at the time of its publication.
This document is an Editor's Draft for review by the Semantic Web Best Practices and Deployment Working Group (hereafter 'the Working Group') and the participants of the public-esw-thes@w3.org mailing list and is subject to change without notice. This document has no formal standing within W3C. Please consult the Working Group's home page and the W3C technical reports index for information about the latest publications by this group. This document may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.
This document is published by the Semantic Web Best Practices and Deployment Working Group, part of the W3C Semantic Web Activity. The Working Group intends the SKOS Core Vocabulary Specification to become a W3C Working Group Note. However, other outcomes are possible within the framework of the W3C process and will be considered in response to deployment experience and feedback from the W3C membership. The Working Group has discussed the potential for SKOS Core to evolve into possible future W3C Recommendation Track work items, and would value feedback on the level of formal standardization that is appropriate.
We encourage public comments. Please send comments to public-esw-thes@w3.org [archive] and start the subject line of the message with "comment:".
Publication as a Working Draft does not imply endorsement by the W3C Membership.
SKOS Core is a supporting RDF vocabulary for publishing concept schemes on the semantic web. Here a 'concept scheme' is defined as 'a description of a set of concepts, which may include a description of relationships between those concepts'.
SKOS Core is also proposed as a standard framework for describing in RDF the more language-oriented types of knowledge organisation system (KOS) such as thesauri, glossaries, terminologies, taxonomies and controlled vocabularies.
It may also be suitable for describing things like weblog category schemes and web directories in RDF.
SKOS Core Namespace
The base namespace for all terms in the SKOS Core vocabulary is:
This document provides an overview of the SKOS Core vocabulary, and is intended as a reference companion to the SKOS Core Guide, which is currently under development and will be published as a working draft shortly.
Guide to Term Summary Tables
Each term (i.e. class or property) of the SKOS Core vocabulary is summarised in this document as a table. Each table may have the following rows:
Class or Property:
URI:
The Universal Resource Identifier.
Label:
A human-readable label.
Definition:
An explanation of the meaning of a class or property.
Comment:
Additional information about meaning and/or proper use.
Example:
An example of the use of a class or property.
Status:
The status (stability level) of the class or property.
Issued:
Date on which the class or property was issued.
Modified:
Date on which the class or property was last modified.
Super-classes:
(Classes only) any declared super-classes.
Super-properties:
(Properties only) any declared super-properties.
Domain:
(Properties only) the declared domain for the property.
Range:
(Properties only) the declared range for the property.
Additional types:
(Properties only) any declared additional types (e.g. owl:TransitiveProperty) for the property.
Inverse of:
(Properties only) any declared inverse properties.
Replaces:
Any deprecated terms which the given term has replaced in recommended usage.
Version info:
A note about the modification and/or history of a class or property.
Replaced By:
(Deprecated terms only) the term to use instead of the deprecated term.
Deprecated:
(Deprecated terms only) the date of last modification (i.e. deprecation) of the term.
SKOS Core Evolution and Management
Each term in the vocabulary has a term status level assigned. The status of a term indicates its level of stability, i.e. how much it may be expected to change in the future. The following status values are allowed:
unstable
The term is unstable, and feedback is welcomed on it's current form and utility (analagous to 'alpha' release in software development). It may currently be poorly defined. It's meaning and/or form may be expected to change at any time. Do not implement mission critical systems that depend on this term persisting in its current form.
testing
The term has gone beyond the raw proposal stage, and is undergoing testing (analagous to 'beta' release in software development). This term may still change in response to feedback from testing, although it may be expected not to undergo any radical change. The cost to early implementors of changing the term will be considered, however the goal of achieving wider interoperability and long-term stability may override those considerations.
stable
No substantial (meaning changing) alterations will take place. Implementors can expect the term to persist in its current form indefinitely.
A term may also be marked as deprecated, in which case instructions will be given on what to use in its place.
SKOS Core has an open-ended maintenance policy, which means that new terms may be added in the future.
Taking Part in SKOS Core Development
SKOS Core is maintained by an open community of developers, users, and domain experts. All development work is discussed via the public-esw-thes@w3.org mailing list. This mailing list is public, and anyone is free to subscribe and/or post mails. A public archive of the mailing list is also available online.
Proposals for additions or modifications to SKOS Core may be made via the public-esw-thes@w3.org mailing list. These are reviewed by the members of the mailing list, and if a reasonable consensus is reached, an action is taken.
Labelled collections can be used with collectable semantic relation properties e.g. skos:narrower, where you would like a set of concepts to be displayed under a 'node label' in the hierarchy.
An ordered collection of concepts, where both the grouping and the ordering are meaningful.
Comment:
Ordered collections can be used with collectable semantic relation properties, where you would like a set of concepts to be displayed in a specific order, and optionally under a 'node label'.
Acronyms, abbreviations, spelling variants, and irregular plural/singular forms may be included among the alternative labels for a concept. Mis-spelled terms are normally included as hidden labels (see skos:hiddenLabel).
A lexical label for a resource that should be hidden when generating visual displays of the resource, but should still be accessible to free text search operations.
A general note not intended for public consumption.
Comment:
This property can be used directly for general notes, or as a super-property for more specific note types where the notes are NOT intended for public consumption.
This property can be used directly for general notes, or as a super-property for more specific note types where the notes are intended for public consumption.
A subject indicator for a concept. [The notion of 'subject indicator' is defined here with reference to the latest definition endorsed by the OASIS Published Subjects Technical Committee.]
Comment:
This property allows subject indicators to be used for concept identification in place of or in addition to directly assigned URIs.
This term has been moved to the 'SKOS Extensions' vocabulary. See http://www.w3.org/2004/02/skos/extensions/
Issued:
2004-03-26
Deprecated:
2004-10-18
Change Log
The complete RDF description of the SKOS Core vocabulary is contained in the following file:
http://www.w3.org/2004/02/skos/core.rdf
The CVS log for this file is included below:
RCS file: /w3ccvs/WWW/2004/02/skos/core.rdf,v
Working file: core.rdf
head: 1.36
branch:
locks: strict
access list:
symbolic names:
keyword substitution: kv
total revisions: 36; selected revisions: 36
description:
----------------------------
revision 1.36
date: 2004/12/17 13:43:58; author: ajm65; state: Exp; lines: +11 -3
Change to skos:related - Changed the definition to mention 'associative relationships', because previous definition too broad, and also to bring in line with BS8723 definition of 'associative relationships'.
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revision 1.35
date: 2004/12/17 13:37:39; author: ajm65; state: Exp; lines: +8 -2
Change to skos:OrderedCollection - The text 'where both the grouping and the ordering are meaningful' added to the definition.
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revision 1.34
date: 2004/12/17 13:34:05; author: ajm65; state: Exp; lines: +9 -1
Change to skos:ConceptScheme - Reworked the definition, in line with new guide. Concept scheme now defined as 'a *description* of a set of concepts, which may include a description of relationships between those concepts'. This change made to make explicit the fact that semantic relationships between concepts may be part of a concept scheme. Also expresses modelling concept scheme as an information resource (hence the 'description' word added).
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revision 1.33
date: 2004/12/17 13:28:08; author: ajm65; state: Exp; lines: +8 -1
Change to skos:Concept - Removed the comment about inferring the meaning of a resource of type skos:Concept, because it was misleading (move to intentional model, where properties of a concept *explain* the meaning of the concept, but do not determine it. This allows for clearer modelling of concepts in multiple schemes).
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revision 1.32
date: 2004/12/17 13:23:26; author: ajm65; state: Exp; lines: +10 -1
Changes to skos:Collection - The word 'meaningful' added to the definition; small change to the comment to make it clearer.
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revision 1.31
date: 2004/12/15 20:11:22; author: ajm65; state: Exp; lines: +21 -5
Added skos:hiddenLabel
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revision 1.30
date: 2004/12/15 19:56:28; author: ajm65; state: Exp; lines: +9 -4
Changed skos:inScheme - no longer a sub-prop of rdfs:isDefinedBy (because the latter is semantically more precise)
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revision 1.29
date: 2004/11/12 15:31:09; author: ajm65; state: Exp; lines: +1 -1
added foaf namespace declaration (was missing)
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revision 1.28
date: 2004/11/11 13:12:58; author: ajm65; state: Exp; lines: +1 -1
Single word change to definition of skos:subjectIndicator
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revision 1.27
date: 2004/11/11 13:07:35; author: ajm65; state: Exp; lines: +30 -0
Spec sections added as subject indicators for all SKOS Core terms
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revision 1.26
date: 2004/11/11 12:52:17; author: ajm65; state: Exp; lines: +4 -3
Added foaf:homepage prop to schema description
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revision 1.25
date: 2004/11/11 12:49:24; author: ajm65; state: Exp; lines: +11 -13
Updated initial XML comment
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revision 1.24
date: 2004/11/11 11:18:57; author: ajm65; state: Exp; lines: +24 -1
Added 'skos:subjectIndicator' property
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revision 1.23
date: 2004/10/22 11:55:42; author: ajm65; state: Exp; lines: +2 -0
Added foaf:Document as domain/range for skos:subject/isSubjectOf
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revision 1.22
date: 2004/10/22 11:52:34; author: ajm65; state: Exp; lines: +1 -1
fix bug in skos:subject
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revision 1.21
date: 2004/10/22 11:42:46; author: ajm65; state: Exp; lines: +54 -3
Added skos:subject, skos:isSubjectOf, skos:primarySubject, skos:isPrimarySubjectOf
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revision 1.20
date: 2004/10/21 16:15:24; author: ajm65; state: Exp; lines: +1 -1
fix bad link in example for editorialNote
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revision 1.19
date: 2004/10/21 14:22:26; author: ajm65; state: Exp; lines: +93 -19
Added historyNote, editorialNote, changeNote.
Modified scopeNote, definition, example: removed domain statement, super-prop changed to publicNote.
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revision 1.18
date: 2004/10/21 14:05:26; author: ajm65; state: Exp; lines: +27 -2
publicNote and privateNote added
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revision 1.17
date: 2004/10/20 17:10:45; author: ajm65; state: Exp; lines: +62 -1
Collections vocabulary added (support for 'node labels' and 'guide terms')
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revision 1.16
date: 2004/10/20 16:36:14; author: ajm65; state: Exp; lines: +24 -10
skos:externalID deprecated (use dc:identifier instead).
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revision 1.15
date: 2004/10/20 15:17:00; author: ajm65; state: Exp; lines: +75 -0
Added a change note to all updated terms
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revision 1.14
date: 2004/10/20 15:09:45; author: ajm65; state: Exp; lines: +17 -2
Updated dct:modified for all terms
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revision 1.13
date: 2004/10/20 15:07:48; author: ajm65; state: Exp; lines: +10 -1
Added new comments
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revision 1.12
date: 2004/10/20 14:59:41; author: ajm65; state: Exp; lines: +223 -193
Former comments on terms deprecated
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revision 1.11
date: 2004/10/20 14:49:37; author: ajm65; state: Exp; lines: +18 -3
Added a skos:definition to all current terms
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revision 1.10
date: 2004/10/20 14:37:48; author: ajm65; state: Exp; lines: +17 -1
Added examples to all current terms
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revision 1.9
date: 2004/10/20 14:31:32; author: ajm65; state: Exp; lines: +25 -25
Added xml:lang to all rdfs:label statements
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revision 1.8
date: 2004/10/20 14:26:31; author: ajm65; state: Exp; lines: +1 -1
Updated date modified for the schema
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revision 1.7
date: 2004/10/18 16:02:44; author: ajm65; state: Exp; lines: +118 -67
The following terms deprecated and replaced by terms in the 'SKOS Extensions' vocabulary
...
'broaderGeneric'
'broaderInstantive'
'broaderPartitive'
'narrowerGeneric'
'narrowerInstantive'
'narrowerPartitive'
'relatedHasPart'
'relatedIsPartOf'
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revision 1.6
date: 2004/08/27 19:37:43; author: ajm65; state: Exp; lines: +25 -1
Added dct:issued for all terms
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revision 1.5
date: 2004/08/19 13:05:05; author: ajm65; state: Exp; lines: +29 -3
Deprecated class skos:TopConcept
Added property skos:hasTopConcept
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revision 1.4
date: 2004/08/03 17:31:13; author: ajm65; state: Exp; lines: +1 -1
error 'ts' changed to 'vs' in namespace declaration
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revision 1.3
date: 2004/08/03 17:10:00; author: ajm65; state: Exp; lines: +75 -5
Following changes:
- doctype changed to 'rdf:RDF'
- entity 'vs' added
- xmlns:vs added
- dct:modified date updated
- dc:title changed to 'SKOS Core RDF Vocabulary'
- dc:contributor added
- term status values added for all terms
- initial XML comment rewritten
- rdfs:isDefinedBy added for al terms
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revision 1.2
date: 2004/03/26 17:06:36; author: danbri; state: Exp; lines: +208 -227
update from al
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revision 1.1
date: 2004/03/18 15:44:12; author: danbri; state: Exp;
swad-e thesaurus work in progress
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Acknowledgements
All current and past members of the public-esw-thes@w3.org mailing list have contributed to the development of this vocabulary, and their contributions are gratefully acknowledged.
