If a property P is a subproperty of property P', then all pairs of resources which are related by P are also related by P'. The term super-property is often used as the inverse of subproperty. If a property P' is a super-property of a property P, then all pairs of resources which are related by P are also related by P'.
This specification does not define a top property that is the super-property of all properties. The basic facilities provided by rdfs:domain and rdfs:range do not provide any direct way to indicate property restrictions that are local to a class. Where P has more than one rdfs:range property, then the resources denoted by the objects of triples with predicate P are instances of all the classes stated by the rdfs:range properties.
The rdfs:range property can be applied to itself. The rdfs:range of rdfs:range is the class rdfs:Class. This states that any resource that is the value of an rdfs:range property is an instance of rdfs:Class. The rdfs:range property is applied to properties. This can be represented in RDF using the rdfs:domain property. The rdfs:domain of rdfs:range is the class rdf:Property. This states that any resource with an rdfs:range property is an instance of rdf:Property.
Where a property P has more than one rdfs:domain property, then the resources denoted by subjects of triples with predicate P are instances of all the classes stated by the rdfs:domain properties. The rdfs:domain property may be applied to itself.
The rdfs:domain of rdfs:domain is the class rdf:Property. This states that any resource with an rdfs:domain property is an instance of rdf:Property. The rdfs:range of rdfs:domain is the class rdfs:Class. This states that any resource that is the value of an rdfs:domain property is an instance of rdfs:Class. The rdfs:domain of rdf:type is rdfs:Resource. The rdfs:range of rdf:type is rdfs:Class. The property rdfs:subClassOf is an instance of rdf:Property that is used to state that all the instances of one class are instances of another.
The rdfs:subClassOf property is transitive. The rdfs:domain of rdfs:subClassOf is rdfs:Class. The rdfs:range of rdfs:subClassOf is rdfs:Class. The property rdfs:subPropertyOf is an instance of rdf:Property that is used to state that all resources related by one property are also related by another. The rdfs:subPropertyOf property is transitive. The rdfs:domain of rdfs:subPropertyOf is rdf:Property. The rdfs:range of rdfs:subPropertyOf is rdf:Property. The rdfs:domain of rdfs:label is rdfs:Resource.
The rdfs:range of rdfs:label is rdfs:Literal. Multilingual labels are supported using the language tagging facility of RDF literals. The rdfs:domain of rdfs:comment is rdfs:Resource. The rdfs:range of rdfs:comment is rdfs:Literal. A textual comment helps clarify the meaning of RDF classes and properties. Such in-line 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 vocabulary. Since RDF vocabularies are expressed as RDF graphs, vocabularies defined in other namespaces may be used to provide richer documentation.
Multilingual documentation is supported through use of the language tagging facility of RDF literals. This specification introduces an RDF vocabulary for describing the meaningful use of properties and classes in RDF data.
For example, an RDF vocabulary might describe limitations on the types of values that are appropriate for some property, or on the classes to which it makes sense to ascribe such properties. RDF Schema provides a mechanism for describing this information, but does not say whether or how an application should use it. For example, while an RDF vocabulary can assert that an author property is used to indicate resources that are instances of the class Person , it does not say whether or how an application should act in processing that range information.
Different applications will use this information in different ways. For example, data checking tools might use this to help discover errors in some data set, an interactive editor might suggest appropriate values, and a reasoning application might use it to infer additional information from instance data.
RDF vocabularies can describe relationships between vocabulary items from multiple independently developed vocabularies. Since IRIs are used to identify classes and properties on the Web, it is possible to create new properties that have a domain or range whose value is a class defined in another namespace.
Additional classes and properties, including constructs for representing containers and RDF statements, and for deploying RDF vocabulary descriptions in the World Wide Web, are defined in this section. RDF containers are resources that are used to represent collections. The same resource may appear in a container more than once.
Unlike containment in the physical world, a container may be contained in itself. Three different kinds of container are defined. Whilst the formal semantics [ RDFMT ] of all three classes of container are identical, different classes may be used to indicate informally further information.
An rdf:Bag is used to indicate that the container is intended to be unordered. This is a preview of subscription content, log in to check access. Beckett D. W3C recommendation. Brickley D. W3C Recommendation. Hayes P. RDF Semantics. A word of caution : although RDFS defines a schema, it does not enforce any constraint on the input of the information. This is in stark constrast with an XML schema whose role is to validate the content of the file.
The RDF schema allows an inference system, called a reasoner in Semantic Web parlance, to infer to entail in the Semantic Web jargon new data from the ones that are given explicitely in the file. Note that nothing in RDF precludes that a ressource be a member of many classes even ones that do not make sense for a human, e. It allows the definition of classes and properties but also of subclasses and subproperties that are not used in this simple example.
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