RDF Schema Diagrams

For some reason the latest (2004) version of the RDF Schema specification does not include the useful diagrams that were included in previous drafts. Maybe they were omitted because the diagrams sacrificed some formalism for the sake of clarity. Nevertheless I found those older diagrams useful for getting my head around some of the concepts, so here they are:

2002 Version

1999 Version

The current 2004 version of the spec does include these useful summary tables:

6.1 RDF classes

  Class name
  comment

rdfs:Resource

The class resource, everything.

rdfs:Literal

The class of literal values, e.g. textual strings and integers.

rdf:XMLLiteral

The class of XML literals values.

rdfs:Class

The class of classes.

rdf:Property

The class of RDF properties.

rdfs:Datatype

The class of RDF datatypes.

rdf:Statement

The class of RDF statements.

rdf:Bag

The class of unordered containers.

rdf:Seq

The class of ordered containers.

rdf:Alt

The class of containers of alternatives.

rdfs:Container

The class of RDF containers.

rdfs:ContainerMembershipProperty

The class of container membership properties, rdf:_1, rdf:_2, …, all of which are sub-properties of ‘member’.

rdf:List

The class of RDF Lists.

6.2 RDF

properties

  Property name
  comment
  domain
  range

rdf:type

The subject is an instance of a class.

rdfs:Resource

rdfs:Class

rdfs:subClassOf

The subject is a subclass of a class.

rdfs:Class

rdfs:subPropertyOf

The subject is a subproperty of a property.

rdf:Property

rdfs:domain

A domain of the subject property.

rdf:Property

rdfs:Class

rdfs:range

A range of the subject property.

rdf:Property

rdfs:Class

rdfs:label

A human-readable name for the subject.

rdfs:Resource

rdfs:Literal

rdfs:comment

A description of the subject resource.

rdfs:Resource

rdfs:Literal

rdfs:member

A member of the subject resource.

rdfs:Resource

rdf:first

The first item in the subject RDF list.

rdf:List

rdfs:Resource

rdf:rest

The rest of the subject RDF list after the first item.

rdf:List

rdfs:seeAlso

Further information about the subject resource.

rdfs:Resource

rdfs:isDefinedBy

The definition of the subject resource.

rdfs:Resource

rdf:value

Idiomatic property used for structured values (see the RDF Primer for an example of its usage).

rdfs:Resource

rdf:subject

The subject of the subject RDF statement.

rdf:Statement

rdfs:Resource

rdf:predicate

The predicate of the subject RDF statement.

rdf:Statement

rdfs:Resource

rdf:object

The object of the subject RDF statement.

rdf:Statement

rdfs:Resource

In addition to these classes and properties, RDF also uses properties called rdf:_1, rdf:_2, rdf:_3… etc., each of which is both a sub-property of rdfs:member and an instance of the class rdfs:ContainerMembershipProperty. There is also an instance of rdf:List called rdf:nil that is an empty rdf:List.