RDF Schema 1.0

The Resource Description Framework (RDF) is a general-purpose language for representing information in the Web. This specification describes how to use RDF to describe RDF vocabularies. This specification also defines a basic vocabulary for this purpose, as well as conventions that can be used by Semantic Web applications to support more sophisticated RDF vocabulary description.

Status of this document

This section describes the status of this document at the time of its publication. Other documents may supersede this document.

The Resource Description Framework is part of the W3C Semantic Web Activity. The goal of this activity, and of RDF specifically, is to produce a language for the exchange of machine-understandable information using the Web. Separate specifications describes the RDF data model and syntax.@@primer etc here

It is inappropriate to use a W3C Working Draft as reference material or to cite them as other than "work in progress". This is work in progress and does not imply endorsement by, or the consensus of W3C. A list of current W3C Recommendations and other technical documents can be found at http://www.w3.org/TR.

Introduction

The language defined in this specification consists of a collection of RDF resources that can be used to describe properties of other RDF resources (including properties) which define application-specific RDF vocabularies. The core vocabulary is defined in a namespace informally called 'rdfs' here, and identified by the URI reference http://www.w3.org/2000/01/rdf-schema#. This specification also uses the prefix 'rdf' to refer to the core RDF namespace http://www.w3.org/1999/02/22-rdf-syntax-ns#.

Editorial Note: this Working Draft does not propose a change to the namespace URIs use, nor to the prefix 'rdfs' traditionally used to indicate the vocabulary description language's namespace URI . The Working Group seek seekback from implementors on the costs and benefits of moving to a new RDFS namespace URI.

RDF Terms

rdfs:Resource

All things described by RDF are called resources, and are members of the class rdfs:Resource.

rdfs:Literal

rdfs:Literal represents to the self-denoting nodes called the 'literals' in the RDF graph structure. Atomic values such as textual strings are examples of RDF literals.

rdfs:Class

This corresponds to the generic concept of a type or category of resource. RDF class membership is used to represent types or categories of resource. Two classes may happen to have the same members, while remaining distinct resources.

rdf:Property

rdf:Property represents those resources that are RDF properties.

rdf:type

The rdf:type property indicates that a resource is a member of a class.

When a resource has an rdf:type property whose value is some specific class, we say that the resource is an instance of the specified class.

The value of an rdf:type property will always be a resource that is an instance of rdfs:Class. The resource known as rdfs:Class is itself a resource of rdf:type rdfs:Class.

rdfs:subClassOf

The rdfs:subClassOf property represents a specialisation relationhip between classes of resource. The rdfs:subClassOf property is transitive.

rdfs:subPropertyOf

The property rdfs:subPropertyOf is an instance of rdf:Property that is used to specify that one property is a specialization of another.

Sub-property hierarchies can be used to express hierarchies of range and domain constraints. All rdfs:range and rdfs:domain properties that apply to an RDF property also apply to each of its sub-properties.

rdfs:range

An instance of rdfs:Property that is used to indicate the class(es) that the values of a property will be members of.

The value of an rdfs:range property is always a Class. The rdfs:range property can itself be used to express this: the rdfs:range of rdfs:range is the class rdfs:Class. This indicates that any resource that is the value of a range property will be a class.

The rdfs:range property is only applied to properties. This can also be represented in RDFusing the rdfs:domain property. The rdfs:domain of rdfs:range is the class rdf:Property. This indicates that the range property applies to resources that are themselves properties.

rdfs:domain

An instance of rdfs:Property that is used to indicate the class(es) that will have as members any resource that has the indicated property.

The rdfs:domain of rdfs:domain is the class rdf:Property. This indicates that the domain property is used on resources that are properties.

The rdfs:range of rdfs:domain is the class rdfs:Class. This indicates that any resource that is the value of a domain property will be a class.

Note: range, domain and sub-property hierarchies

rdfs:label

The rdfs:label property is used to provide a human-readable version of a resource's name.

rdfs:comment

The rdfs:comment property is used to provide a human-readable description of a resource.

A textual comment helps clarify the meaning of RDF classes and properties. Such inline documentation complements the use of both formal techniques (Ontology and rule languages) and informal (prose documentation, examples, test cases). A variety of documentation forms can be combined to indicate the intended meaning of the classes and properties described in an RDF Schema.

Multilingual documentation of schemas is supported at the syntactic level through use of the xml:lang language tagging facility. Since RDF schemas are expressed as RDF graphs, vocabularies defined in other namespaces may be used to provide richer documentation.

rdfs:Container	The `rdfs:Container` class is used to represent the core RDF Container classes, ie. `rdf:Bag`, `rdf:Seq`, `rdf:Alt`.
rdf:Bag	The `rdf:Bag` class represents RDF's 'Bag' container construct, and is a subclass of `rdfs:Container`.
rdf:Seq	The `rdf:Seq` class represents RDF's 'Sequence' container construct, and is a subclass of `rdfs:Container`.
rdf:Alt	The `rdf:Seq` class represents RDF's 'Alt' container construct, and is a subclass of `rdfs:Container`.
rdfs:ContainerMembershipProperty	The `rdfs:ContainerMembershipProperty` class has as members the properties `_1, _2, _3 ...` that can be used to indicate membership of Bag, Seq and Alt containers. `rdfs:ContainerMembershipProperty` is a subclass of `rdf:Property`. Each container membership property is a `rdfs:subPropertyOf` the `rdfs:member` property.
rdfs:member	The `rdfs:member` property is a super-property of the container membership properties.

rdfs:seeAlso	The property `rdfs:seeAlso` is used to indicate a resource that might provide additional information about the subject resource.
rdfs:isDefinedBy	The property `rdfs:isDefinedBy` is a subproperty of `rdfs:seeAlso`, and indicates the resource defining the subject resource. As with `rdf:seeAlso`, this property can be applied to any instance of `rdfs:Resource` and may have as its value any `rdfs:Resource`.
rdf:value	Identifies the principal value (usually a string) of a property when the property value is a structured resource.
rdf:Statement	The `rdf:Statement` class represents statements about the properties of resources. `rdf:Statement` is the domain of the properties `rdf:predicate`, `rdf:subject` and `rdf:object`. Different individual `rdf:Statement` instances may happen to have the same values for their predicate, subject and object properties.
rdf:subject	The subject of an RDF statement. The `rdf:subject` property indicates a resource that is the subject of some RDF statement. The `rdfs:domain` of `rdf:subject` is `rdf:Statement` and the `rdfs:range` is `rdfs:Resource`. This property can be used to specify the resource described by an RDF statement.
rdf:predicate	The predicate of an RDF statement. The `rdfs:domain` of `rdf:predicate` is `rdf:Statement` and the `rdfs:range` is `rdfs:Resource`. This property can be used to specify the predicate used in an RDF statement.
rdf:object	The object of an RDF statement. The `rdfs:domain` of `rdf:object` is `rdf:Statement`. No range is defined for this property since values of `rdfs:object` can include both Literals and Resources. This property can be used to specify the object of an RDF statement.

RDF Schema 1.0

W3C Working Draft, April 23 2002

Abstract

Status of this document

Contents

Introduction

RDF Terms

Note: range, domain and sub-property hierarchies

RDF Container Classes and Properties

RDF Utility Classes and Properties

References

Normative References @@TODO:update/check