An RDF vocabulary for describing the basic structure and content of concept schemes such as thesauri, classification schemes, subject heading lists, taxonomies, 'folksonomies', other types of controlled vocabulary, and also concept schemes embedded in glossaries and terminologies.
Participants in W3C's Semantic Web Deployment Working Group.
SKOS Core Vocabulary
alternative 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).
An alternative lexical label for a resource.
The range of skos:altLabel is the class of RDF plain literals.
skos:prefLabel, skos:altLabel and skos:hiddenLabel are pairwise disjoint properties.
definition
A statement or formal explanation of the meaning of a concept.
hidden label
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.
The range of skos:hiddenLabel is the class of RDF plain literals.
preferred label
No two concepts in the same concept scheme may have the same value for skos:prefLabel in a given language.
The preferred lexical label for a resource, in a given language.
The range of skos:prefLabel is the class of RDF plain literals.
broader match
skos:broadMatch is used to state a hierarchical mapping link between two conceptual resources in different concept schemes.
has broader
A concept that is more general in meaning.
Broader concepts are typically rendered as parents in a concept hierarchy (tree).
By convention, skos:broader is only used to assert an immediate (i.e. direct) hierarchical link between two conceptual resources.
broader transitive
By convention, skos:broaderTransitive is not used to make assertions. Rather, the properties can be used to draw inferences about the transitive closure of the hierarchical relation, which is useful e.g. when implementing a simple query expansion algorithm in a search application.
skos:broaderTransitive is a transitive superproperty of skos:broader.
change note
A note about a modification to a concept.
exact match
skos:closeMatch is used to link two concepts that are sufficiently similar that they can be used interchangeably in some information retrieval applications. In order to avoid the possibility of "compound errors" when combining mappings across more than two concept schemes, skos:closeMatch is not declared to be a transitive property.
editorial note
A note for an editor, translator or maintainer of the vocabulary.
skos:exactMatch is disjoint with each of the properties skos:broadMatch and skos:relatedMatch.
skos:exactMatch is used to link two concepts, indicating a high degree of confidence that the concepts can be used interchangeably across a wide range of information retrieval applications. skos:exactMatch is a transitive property, and is a sub-property of skos:closeMatch.
example
An example of the use of a concept.
has top concept
A top level concept in the concept scheme.
history note
A note about the past state/use/meaning of a concept.
in scheme
A concept may be a member of more than one concept scheme.
A concept scheme in which the concept is included.
mapping relation
Definition
These concept mapping relations mirror semantic relations, and the data model defined below is similar (with the exception of skos:exactMatch) to the data model defined for semantic relations. A distinct vocabulary is provided for concept mapping relations, to provide a convenient way to differentiate links within a concept scheme from links between concept schemes. However, this pattern of usage is not a formal requirement of the SKOS data model, and relies on informal definitions of best practice.
member
A member of a collection.
member list
An RDF list containing the members of an ordered collection.
For any resource, every item in the list given as the value of the skos:memberList property is also a value of the skos:member property.
narrower match
skos:narrowMatch is used to state a hierarchical mapping link between two conceptual resources in different concept schemes.
has narrower
A concept that is more specific in meaning.
Narrower concepts are typically rendered as children in a concept hierarchy (tree).
narrower transitive
skos:narrowerTransitive is a transitive superproperty of skos:broader. By convention, skos:narrowerTransitive is not intended to be used in assertions, but provides a mechanism whereby the transitive closure of skos:narrower can be queried.
By convention, skos:narrowerTransitive is not used to make assertions. Rather, the properties can be used to draw inferences about the transitive closure of the hierarchical relation, which is useful e.g. when implementing a simple query expansion algorithm in a search application.
note
A general note, for any purpose.
This property may be used directly, or as a super-property for more specific note types.
related to
A concept with which there is an associative semantic relationship.
skos:related is disjoint with skos:broaderTransitive
related match
skos:relatedMatch is used to state an associative mapping link between two conceptual resources in different concept schemes.
scope note
A note that helps to clarify the meaning of a concept.
semantic relation
A concept related by meaning.
This property should not be used directly, but as a super-property for all properties denoting a relationship of meaning between concepts.
top concept in scheme
Relates a concept to the concept scheme that it is a top level concept of.
notation
A notation, also known as classification code, is a string of characters such as "T58.5" or "303.4833" used to uniquely identify a concept within the scope of a given concept scheme.
By convention, skos:notation is used with a typed literal in the object position of the triple.
Collection
A meaningful collection of concepts.
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.
Concept
An abstract idea or notion; a unit of thought.
Concept Scheme
A concept scheme may be defined to include concepts from different sources.
A set of concepts, optionally including statements about semantic relationships between those concepts.
Thesauri, classification schemes, subject heading lists, taxonomies, 'folksonomies', and other types of controlled vocabulary are all examples of concept schemes. Concept schemes are also embedded in glossaries and terminologies.
Ordered Collection
An ordered collection of concepts, where both the grouping and the ordering are meaningful.
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'.