Copyright © 2003 W3C ® ( MIT , ERCIM , Keio ), All Rights Reserved. W3C liability , trademark , document use and software licensing rules apply.
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 defines a vocabulary for this purpose and defines other built-in RDF vocabulary initially specified in the RDF Model and Syntax Specification.
<h2> <a id="ch_sotd" name="ch_sotd"> </a>This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the <a href="http://www.w3.org/TR/"> W3C technical reports index at http://www.w3.org/TR/.
This is a W3C <a href="http://www.w3.org/2003/06/Process-20030618/tr.html#RecsWD"> Last Call Working Draft of the RDF Core Working Group and has been produced as part of the W3C Semantic Web Activity ( Activity Statement ).
Detailed changes from the previous <a href="http://www.w3.org/TR/2003/WD-rdf-schema-20030123/"> 23 January 10 October 2003 working draft are described in the Changes section .
This Working Draft document is in the Last Call review period, which ends on 07 November 2003. This Last Call publication consolidates changes and editorial improvements undertaken in response to feedback received during the <a href="http://www.w3.org/2003/06/Process-20030618/tr#last-call"> previous Last Call publication of the RDFCore specifications which began on 05 September 23 January 2003. A list of the Last Call issues addressed by the Working Group is deleted text: <a href="http://www.w3.org/2001/sw/RDFCore/20030123-issues/"> also available </a>. available. This document has been endorsed by the RDF Core Working Group.
This document is being released for review by W3C Members and other interested parties to encourage feedback and comments, especially with regard to how the changes made affect existing implementations and content.
In conformance with W3C policy requirements, known patent and IPR constraints associated with this Working Draft are detailed on the RDF Core Working Group Patent Disclosure page.
Comments on this document are invited and should be sent to the public mailing list www-rdf-comments@w3.org . An archive of comments is available at http://lists.w3.org/Archives/Public/www-rdf-comments/ .
deleted text: This is a public W3C Working Draft for review by W3C Members and other interested parties. This section describes the status of this document at the time of its publication. Publication as a Working Draft does not imply endorsement by the W3C Membership. This is a draft document and 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. A list of current W3C Recommendations and other technical documents can be found at <a href="/TR/"> http://www.w3.org/TR/ </a>. http://www.w3.org/TR/.
deleted text: <!-- ................ end status ...................... -->1. Introduction
2. Classes
2.1 rdfs:Resource
2.2 rdfs:Class
2.3 rdfs:Literal
2.4 rdfs:Datatype
2.5 rdf:XMLLiteral
2.6 rdf:Property
3. Properties
3.1 rdfs:range
3.2 rdfs:domain
3.3 rdf:type
3.4 rdfs:subClassOf
3.5 rdfs:subPropertyOf
3.6 rdfs:label
3.7 rdfs:comment
4. Using the Domain and Range vocabulary (Informative)
5. Other vocabulary
5.1 Container Classes and Properties
5.1.1 rdfs:Container
5.1.2 rdf:Bag
5.1.3 rdf:Seq
5.1.4 rdf:Alt
5.1.5 rdfs:ContainerMembershipProperty
5.1.6 rdfs:member
5.2 RDF Collections
5.2.1 rdf:List
5.2.2 rdf:first
5.2.3 rdf:rest
5.2.4 rdf:nil
5.3 Reification Vocabulary
5.3.1 rdf:Statement
5.3.2 rdf:subject
5.3.3 rdf:predicate
5.3.4 rdf:object
5.4 Utility Properties
5.4.1 rdfs:seeAlso
5.4.2 rdfs:isDefinedBy
5.4.3 rdf:value
6. RDF Schema summary (Informative)
6.1 Classes
6.2 Properties
7. References
7.1 Normative References
7.2 Informational References
8. Acknowledgments
Appendix A RDF Schema as RDF/XML
The Resource Description Framework (RDF) is a general-purpose language for representing information in the Web.
This specification is one of several [ RDF-PRIMER ] [ RDF-SYNTAX ] [ RDF-CONCEPTS ] [ RDF-SEMANTICS ] [ RDF-TESTS ] related to RDF. The reader is referred to the <a href="http://www.w3.org/TR/2003/WD-rdf-primer-20030905/#rdfschema"> RDF schema chapter in the RDF Primer [ RDF-PRIMER ] for an informal introduction and examples of the use of the concepts specified in this document.
This specification introduces RDF's vocabulary description language, RDF Schema. It is complemented by several companion documents which describe RDF's XML encoding [ RDF-SYNTAX ], mathematical foundations [ RDF-SEMANTICS ] and Resource Description Framework (RDF): Concepts and Abstract Syntax [ RDF-CONCEPTS ]. The RDF Primer [ RDF-PRIMER ] provides an informal introduction and examples of the use of the concepts specified in this document.
This document is intended to provide a clear specification of the RDF vocabulary description language to those who find the formal semantics specification, RDF Semantics [ RDF-SEMANTICS ] daunting. Thus, this document duplicates material also specified in the RDF Semantics specification . Where there is disagreement between this document and the RDF Semantics specification, the RDF Semantics specification should be taken to be correct.
RDF properties may be thought of as attributes of resources and in this sense correspond to traditional attribute-value pairs. RDF properties also represent relationships between resources.
RDF however, provides no mechanisms for describing these properties, nor does it provide any mechanisms for describing the relationships between these properties and other resources. That is the role of the RDF vocabulary description language, RDF Schema. RDF Schema defines classes and properties that may be used to describe classes, properties and other resources.
This document does not specify a vocabulary of descriptive properties such as "author". Instead it specifies mechanisms that may be used to name and describe properties and the classes of resource they describe.
RDF's vocabulary description language, RDF Schema, is a semantic extension (as defined in [ RDF-SEMANTICS ]) of RDF. It provides mechanisms for describing groups of related resources and the relationships between these resources. RDF Schema vocabulary descriptions are written in RDF using the terms described in this document. These resources are used to determine characteristics of other resources, such as the domains and ranges of properties.
The
RDF
vocabulary
description
language
class
and
property
system
is
similar
to
the
type
systems
of
object-oriented
programming
languages
such
as
Java.
RDF
differs
from
many
such
systems
in
that
instead
of
defining
a
class
in
terms
of
the
properties
its
instances
may
have,
the
RDF
vocabulary
description
language
describes
properties
in
terms
of
the
classes
of
resource
to
which
they
apply.
This
is
the
role
of
the
domain
and
range
mechanisms
described
in
this
specification.
For
example,
we
could
define
the
eg:author
property
to
have
a
domain
of
eg:Document
and
a
range
of
eg:Person
,
whereas
a
classical
object
oriented
system
might
typically
define
a
class
eg:Book
with
an
attribute
called
eg:author
of
type
eg:Person
.
Using
the
RDF
approach,
it
is
easy
for
others
to
subsequently
define
additional
properties
with
a
domain
of
eg:
Document
or
a
range
of
eg:Person
.
This
can
be
done
without
the
need
to
re-define
the
original
description
of
these
classes.
One
benefit
of
the
RDF
property-centric
approach
is
that
it
allows
anyone
to
extend
the
description
of
existing
resources,
one
of
the
architectural
principles
of
the
Web
[
BERNERS-LEE98
].
This specification does not attempt to enumerate all the possible forms of vocabulary description that are useful for representing the meaning of RDF classes and properties. Instead, the RDF vocabulary description strategy is to acknowledge that there are many techniques through which the meaning of classes and properties can be described. Richer vocabulary or 'ontology' languages such as DAML+OIL, W3C's [ OWL ] language, inference rule languages and other formalisms (for example temporal logics) will each contribute to our ability to capture meaningful generalizations about data in the Web. RDF vocabulary designers can create and deploy Semantic Web applications using the RDF vocabulary description language 1.0 facilities, while exploring richer vocabulary description languages that share this general approach.
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) in application-specific RDF vocabularies. The core vocabulary is defined in a namespace informally called 'rdfs' here. That namespace is identified by the URI-Reference http://www.w3.org/2000/01/rdf-schema# and is associated with the prefix 'rdfs'. This specification also uses the prefix 'rdf' to refer to the <a href="http://www.w3.org/TR/2003/WD-rdf-syntax-grammar-20030905/#section-Namespace"> RDF namespace http://www.w3.org/1999/02/22-rdf-syntax-ns#.
For convenience and readability, this specification uses an abbreviated form to represent URI-References. A name of the form prefix:suffix should be interpreted as a URI-Reference consisting of the URI-Reference associated with the prefix concatenated with the suffix.
Resources
may
be
divided
into
groups
called
classes.
The
members
of
a
class
are
known
as
instances
of
the
class.
Classes
are
themselves
resources.
They
are
often
identified
by
<a href="http://www.w3.org/TR/2003/WD-rdf-concepts-20030905/#section-Graph-URIref">
RDF
URI
References
and
may
be
described
using
RDF
properties.
The
rdf:type
property
may
be
used
to
state
that
a
resource
is
an
instance
of
a
class.
RDF distinguishes between a class and the set of its instances. Associated with each class is a set, called the class extension of the class, which is the set of the instances of the class. Two classes may have the same set of instances but be different classes. For example, the tax office may define the class of people living at the same address as the editor of this document. The Post Office may define the class of people whose address has the same zip code as the address of the author. It is possible for these classes to have exactly the same instances, yet to have different properties. Only one of the classes has the property that it was defined by the tax office, and only the other has the property that it was defined by the Post Office.
A class may be a member of its own class extension and may be an instance of itself.
The
group
of
resources
that
are
RDF
Schema
classes
is
itself
a
class
called
rdfs:Class
.
If
a
class
C
is
a
subclass
of
a
class
C',
then
all
instances
of
C
will
also
be
instances
of
C'.
The
rdfs:subClassOf
property
may
be
used
to
state
that
one
class
is
a
subclass
of
another.
The
term
super-class
is
used
as
the
inverse
of
subclass.
If
a
class
C'
is
a
super-class
of
a
class
C,
then
all
instances
of
C
are
also
instances
of
C'.
The RDF Concepts and Abstract Syntax [ RDF-CONCEPTS ] specification defines the RDF concept of an <a href="http://www.w3.org/TR/2003/WD-rdf-concepts-20030905/#section-Datatypes"> RDF datatype . All datatypes are classes. The instances of a class that is a datatype are the members of the value space of the datatype.
All
things
described
by
RDF
are
called
resources
,
and
are
instances
of
the
class
rdfs:Resource
.
This
is
the
class
of
everything.
All
other
classes
are
subclasses
of
this
class.
rdfs:Resource
is
an
instance
of
rdfs:Class
.
This
is
the
class
of
resources
that
are
RDF
classes.
rdfs:Class
is
an
instance
of
rdfs:Class.
The
class
rdfs:Literal
is
the
class
of
<a href="http://www.w3.org/TR/2003/WD-rdf-concepts-20030905/#section-Literals">
literal
values
such
as
strings
and
integers.
Property
values
such
as
textual
strings
are
examples
of
RDF
literals.
Literals
may
be
<a href="http://www.w3.org/TR/2003/WD-rdf-concepts-20030905/#dfn-plain-literal">
plain
or
<a href="http://www.w3.org/TR/2003/WD-rdf-concepts-20030905/#dfn-typed-literal">
typed
.
A
typed
literal
is
an
instance
of
a
datatype
class.
This
specification
does
not
define
the
class
of
plain
literals.
rdfs:Literal
is
an
instance
of
rdfs:Class
.
rdfs:Literal
is
a
subclass
of
rdfs:Resource
.
rdfs:Datatype
is
the
class
of
datatypes.
All
instances
of
rdfs:Datatype
correspond
to
the
<a href="http://www.w3.org/TR/2003/WD-rdf-concepts-20030905/#section-Datatypes">
RDF
model
of
a
datatype
described
in
the
RDF
Concepts
specification
[
RDF-CONCEPTS
].
rdfs:Datatype
is
both
an
instance
of
and
a
subclass
of
rdfs:Class
.
Each
instance
of
rdfs:Datatype
is
a
subclass
of
rdfs:Literal.
The
class
rdf:XMLLiteral
is
the
class
of
<a href="http://www.w3.org/TR/2003/WD-rdf-concepts-20030905/#dfn-rdf-XMLLiteral">
XML
literal
values
.
rdf:XMLLiteral
is
an
instance
of
rdfs:Datatype
and
a
subclass
of
rdfs:Literal
.
rdf:Property
is
the
class
of
RDF
properties.
rdf:Property
is
an
instance
of
rdfs:Class
.
The RDF Concepts and Abstract Syntax specification [ RDF-CONCEPTS ] describes the concept of an RDF property as a relation between subject resources and object resources.
This
specification
defines
the
concept
of
subproperty.
The
rdfs:subPropertyOf
property
may
be
used
to
state
that
one
property
is
a
subproperty
of
another.
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.
Note
:
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.
Although
it
is
possible
to
combine
use
rdfs:domain
and
rdfs:range
with
sub-property
hierarchies,
direct
support
for
such
declarations
are
provided
by
richer
<a href="http://www.w3.org/2001/sw/WebOnt">
Web
Ontology
languages
such
as
[
OWL
].
rdfs:range
is
an
instance
of
rdf:Property
that
is
used
to
state
that
the
values
of
a
property
are
instances
of
one
or
more
classes.
The triple
P rdfs:range C
states
that
P
is
an
instance
of
the
class
rdf:Property
,
that
C
is
an
instance
of
the
class
rdfs:Class
and
that
the
resources
denoted
by
the
objects
of
triples
whose
predicate
is
P
are
instances
of
the
class
C.
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
.
rdfs:domain
is
an
instance
of
rdf:Property
that
is
used
to
state
that
any
resource
that
has
a
given
property
is
an
instance
of
one
or
more
classes.
A triple of the form:
P rdfs:domain C
states
that
P
is
an
instance
of
the
class
rdf:Property
,
that
C
is
a
instance
of
the
class
rdfs:Class
and
that
the
resources
denoted
by
the
subjects
of
triples
whose
predicate
is
P
are
instances
of
the
class
C.
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
.
rdf:type
is
an
instance
of
rdf:Property
that
is
used
to
state
that
a
resource
is
an
instance
of
a
class.
A triple of the form:
R rdf:type C
states
that
C
is
an
instance
of
rdfs:Class
and
R
is
an
instance
of
C.
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.
A triple of the form:
C1 rdfs:subClassOf C2
states
that
C1
is
an
instance
of
rdfs:Class
,
C2
is
an
instance
of
rdfs:Class
and
C1
is
a
subclass
of
C2.
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.
A triple of the form:
P1 rdfs:subPropertyOf P2
states
that
P1
is
an
instance
of
rdf:Property
,
P2
is
an
instance
of
rdf:Property
and
P1
is
a
subproperty
of
P2.
The
rdfs:subPropertyOf
property
is
transitive.
The
rdfs:domain
of
rdfs:subPropertyOf
is
rdf:Property
.
The
rdfs:range
of
rdfs:subPropertyOf
is
rdf:Property
.
rdfs:label
is
an
instance
of
rdf:Property
that
may
be
used
to
provide
a
human-readable
version
of
a
resource's
name.
A triple of the form:
R rdfs:label L
states that L is a human readable label for R.
The
rdfs:domain
of
rdfs:label
is
rdfs:Resource
.
The
rdfs:range
of
rdfs:label
is
rdfs:Literal
.
Multilingual labels are supported using the <a href="http://www.w3.org/TR/2003/WD-rdf-concepts-20030905/#section-Graph-Literal"> language tagging facility of RDF literals.
rdfs:comment
is
an
instance
of
rdf:Property
that
may
be
used
to
provide
a
human-readable
description
of
a
resource.
A triple of the form:
R rdfs:comment L
states that L is a human readable description of R.
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 <a href="http://www.w3.org/TR/2003/WD-rdf-concepts-20030905/#section-Graph-Literal"> 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.
The
RDF
Vocabulary
Description
language
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
URI-References
are
used
to
identify
classes
and
properties
in
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. An <a href="http://www.w3.org/TR/2003/WD-rdf-primer-20030905/#containers"> introduction to RDF containers with examples may be found in the RDF Primer [ RDF-PRIMER ]. 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 [ RDF-SEMANTICS ] 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. An rdf:Seq is used to indicate that the order indicated by the numerical order of the container member ship properties of the container is intended to be significant. An rdf:Alt container is used to indicate that typical processing of the container will be to select one of the members.
Just as a hen house may have the property that it is made of wood, that does not mean that all the hens it contains are made of wood, a property of a container is not necessarily a property of all of its members.
RDF containers are defined by the following classes and properties.
The
rdfs:Container
class
is
a
super-class
of
the
RDF
Container
classes,
i.e.
rdf:Bag
,
rdf:Seq
,
rdf:Alt
.
The
rdf:Bag
class
is
the
class
of
RDF
'Bag'
containers.
It
is
a
subclass
of
rdfs:Container
.
Whilst
formally
it
is
no
different
from
an
rdf:Seq
or
an
rdf:Alt
,
the
rdf:Bag
class
is
used
conventionally
to
indicate
to
a
human
reader
that
the
container
is
intended
to
be
unordered.
The
rdf:Seq
class
is
the
class
of
RDF
'Sequence'
containers.
It
is
a
subclass
of
rdfs:Container
.
Whilst
formally
it
is
no
different
from
an
rdf:Bag
or
an
rdf:Alt
,
the
rdf:Seq
class
is
used
conventionally
to
indicate
to
a
human
reader
that
the
numerical
ordering
of
the
container
membership
properties
of
the
container
is
intended
to
be
significant.
The
rdf:Alt
class
is
the
class
of
RDF
'Alternative'
containers.
It
is
a
subclass
of
rdfs:Container
.
Whilst
formally
it
is
no
different
from
an
rdf:Seq
or
an
rdf:Bag
,
the
rdf:Alt
class
is
used
conventionally
to
indicate
to
a
human
reader
that
typical
processing
will
be
to
select
one
of
the
members
of
the
container.
The
first
member
of
the
container,
i.e.
the
value
of
the
rdf:_1
property,
is
the
default
choice.
The
rdfs:ContainerMembershipProperty
class
has
as
instances
the
properties
rdf:_1,
rdf:_2,
rdf:_3
...
that
are
used
to
state
that
a
resource
is
a
member
of
a
container.
rdfs:ContainerMembershipProperty
is
a
subclass
of
rdf:Property
.
Each
instance
of
rdfs:ContainerMembershipProperty
is
an
rdfs:subPropertyOf
the
rdfs:member
property.
Given a container C, a triple of the form:
C rdf:_nnn O
where nnn is the decimal representation of an integer greater than 0 with no leading zeros, states that O is a member of the container C.
Container membership properties may be applied to resources other than containers.
rdfs:member
is
an
instance
of
rdf:Property
that
is
a
super-property
of
all
the
container
membership
properties
i.e.
each
container
membership
property
has
an
rdfs:subPropertyOf
relationship
to
the
property
rdfs:member
.
The
rdfs:domain
of
rdfs:member
is
rdfs:Resource
.
The
rdfs:range
of
rdfs:member
is
rdfs:Resource
.
RDF containers are open in the sense that the core RDF specifications define no mechanism to state that there are no more members. The RDF Collection vocabulary of classes and properties can describe a closed collection, i.e. one that can have no more members. The reader is referred to the <a href="http://www.w3.org/TR/2003/WD-rdf-primer-20030905/#collections"> collections section of the RDF primer for an informal introduction to collections with examples.
A collection is represented as a list of items, a representation that will be familiar to those with experience of Lisp and similar programming languages. There is a <a href="http://www.w3.org/TR/2003/WD-rdf-syntax-grammar-20030905/#section-Syntax-parsetype-Collection"> shorthand notation in the RDF/XML syntax specification [ RDF-SYNTAX ] for representing collections.
Note : RDFS does not require that there be only one first element of a list-like structure, or even that a list-like structure have a first element.
rdf:List
is
an
instance
of
rdfs:Class
that
can
be
used
to
build
descriptions
of
lists
and
other
list-like
structures.
rdf:first
is
an
instance
of
rdf:Property
that
can
be
used
to
build
descriptions
of
lists
and
other
list-like
structures.
A triple of the form:
L rdf:first O
states that there is a first-element relationship between L and O.
The
rdfs:domain
of
rdf:first
is
rdf:List
.
The
rdfs:range
of
rdf:first
is
rdfs:Resource
.
rdf:rest
is
an
instance
of
rdf:Property
that
can
be
used
to
build
descriptions
of
lists
and
other
list-like
structures.
A triple of the form:
L rdf:rest O
states that there is a rest-of-list relationship between L and O.
The
rdfs:domain
of
rdf:rest
is
rdf:List
.
The
rdfs:range
of
rdf:rest
is
rdf:List
.
The
resource
rdf:nil
is
an
instance
of
rdf:List
that
can
be
used
to
represent
an
empty
list
or
other
list-like
structure.
A triple of the form:
L rdf:rest rdf:nil
states
that
L
is
an
instance
of
rdf:List
that
has
one
item;
that
item
can
be
indicated
using
the
rdf:first
property.
The original RDF Model and Syntax Specification [ RDFMS ] defined a vocabulary for describing RDF statements without stating them. [ RDFMS ] did not provide a formal semantics for this vocabulary, and the informal definition that was provided was somewhat inconsistent. The current RDF specification does not assign a normative formal semantics to this vocabulary. However, an intended meaning of this vocabulary (which generally clarifies the intent of the [ RDFMS ] definition) is described here. An informal introduction to the reification vocabulary, with examples, may be found in the RDF Primer [ <a href="http://www.w3.org/TR/2003/WD-rdf-primer-20030905/#reification"> RDF-PRIMER ].
rdf:Statement
is
an
instance
of
rdfs:Class.
It
is
intended
to
represent
the
class
of
RDF
statements.
An
RDF
statement
is
the
statement
made
by
a
token
of
an
RDF
<a href="http://www.w3.org/TR/2003/WD-rdf-concepts-20030905/#section-triples">
triple
.
The
subject
of
an
RDF
statement
is
the
instance
of
rdfs:Resource
identified
by
the
subject
of
the
triple.
The
predicate
of
an
RDF
statement
is
the
instance
of
rdf:Property
identified
by
the
predicate
of
the
triple.
The
object
of
an
RDF
statement
is
the
instance
of
rdfs:Resource
identified
by
the
object
of
the
triple.
rdf:Statement
is
in
the
domain
of
the
properties
rdf:predicate
,
rdf:subject
and
rdf:object
.
Different
individual
rdf:Statement
instances
may
have
the
same
values
for
their
rdf:predicate
,
rdf:subject
and
rdf:object
properties.
rdf:subject
is
an
instance
of
rdf:Property
that
is
used
to
state
the
subject
of
a
statement.
A triple of the form:
S rdf:subject R
states
that
S
is
an
instance
of
rdf:Statement
and
that
the
subject
of
S
is
R.
The
rdfs:domain
of
rdf:subject
is
rdf:Statement
.
The
rdfs:range
of
rdf:subject
is
rdfs:Resource
.
rdf:predicate
is
an
instance
of
rdf:Property
that
is
used
to
state
the
predicate
of
a
statement.
A triple of the form:
S rdf:predicate P
states
that
S
is
an
instance
of
rdf:Statement
,
that
P
is
an
instance
of
rdf:Property
and
that
the
<a href="http://www.w3.org/TR/2003/WD-rdf-concepts-20030905/#section-data-model">
predicate
of
S
is
P.
The
rdfs:domain
of
rdf:predicate
is
rdf:Statement
and
the
rdfs:range
is
rdf:Property
.
rdf:object
is
an
instance
of
rdf:Property
that
is
used
to
state
the
object
of
a
statement.
A triple of the form:
S rdf:object O
states
that
S
is
an
instance
of
rdf:Statement
and
that
the
object
of
S
is
O.
The
rdfs:domain
of
rdf:object
is
rdf:Statement
.
The
rdfs:range
of
rdf:object
is
rdfs:Resource
.
The following utility classes and properties are defined in the RDF core namespaces.
rdfs:seeAlso
is
an
instance
of
rdf:Property
that
is
used
to
indicate
a
resource
that
might
provide
additional
information
about
the
subject
resource.
A triple of the form:
S rdfs:seeAlso O
states that the resource O may provide additional information about S. It may be possible to retrieve representations of O from the Web, but this is not required. When such representations may be retrieved, no constraints are placed on the format of those representations.
The
rdfs:domain
of
rdfs:seeAlso
is
rdfs:Resource
.
The
rdfs:range
of
rdfs:seeAlso
is
rdfs:Resource
.
rdfs:isDefinedBy
is
an
instance
of
rdf:Property
that
is
used
to
indicate
a
resource
defining
the
subject
resource.
This
property
may
be
used
to
indicate
an
RDF
vocabulary
in
which
a
resource
is
described.
A triple of the form:
S rdfs:isDefinedBy O
states
that
the
resource
O
defines
S.
It
may
be
possible
to
retrieve
representations
of
O
from
the
Web,
but
this
is
not
required.
When
such
representations
may
be
retrieved,
no
constraints
are
placed
on
the
format
of
those
representations.
rdfs:isDefinedBy
is
a
subproperty
of
rdfs:seeAlso
.
The
rdfs:domain
of
rdfs:isDefinedBy
is
rdfs:Resource
.
The
rdfs:range
of
rdfs:isDefinedBy
is
rdfs:Resource
.
rdf:value
is
an
instance
of
rdf:Property
that
may
be
used
in
describing
structured
values.
rdf:value has no meaning on its own. It is provided as a piece of vocabulary that may be used in idioms such as illustrated in <a href="http://www.w3.org/TR/2003/WD-rdf-primer-20030905/#example16"> example 16 of the RDF primer [ RDF-PRIMER ]. Despite the lack of formal specification of the meaning of this property, there is value in defining it to encourage the use of a common idiom in examples of this kind.
The
rdfs:domain
of
rdf:value
is
rdfs:Resource
.
The
rdfs:range
of
rdf:value
is
rdfs:Resource
.
This table presents an overview of the vocabulary of RDF, drawing together vocabulary originally defined in the RDF Model and Syntax specification with classes and properties that originate with RDF Schema.
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. |
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:Class |
rdfs:subPropertyOf | The subject is a subproperty of a property. | rdf: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 | 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 | rdf:List |
rdfs:seeAlso | Further information about the subject resource. | rdfs:Resource | rdfs:Resource |
rdfs:isDefinedBy | The definition of the subject resource. | rdfs:Resource | rdfs:Resource |
rdf:value | Idiomatic property used for structured values (see the RDF Primer for <a href="http://www.w3.org/TR/2003/WD-rdf-primer-20030905/#example16"> an example of its usage). | rdfs:Resource | 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 | rdf:Property |
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
.
The RDF Schema design was originally produced by the RDF Schema Working Group (1997-2000). The current specification is largely an editorial clarification of that design, and has benefited greatly from the hard work of the RDF Core Working Group members , and from implementation feedback from many members of the RDF Interest Group .
David Singer of IBM was the chair of the original RDF Schema group throughout most of the development of this specification; we thank David for his efforts and thank IBM for supporting him and us in this endeavor. Particular thanks are also due to Andrew Layman for his editorial work on early versions of this specification.
The original RDF Schema Working Group membership included:
Nick Arnett (Verity), Dan Brickley (ILRT / University of Bristol), Walter Chang (Adobe), Sailesh Chutani (Oracle), Ron Daniel (DATAFUSION), Charles Frankston (Microsoft), Joe Lapp (webMethods Inc.), Patrick Gannon (CommerceNet), RV Guha (Epinions, previously of Netscape Communications), Tom Hill (Apple Computer), Renato Iannella (DSTC), Sandeep Jain (Oracle), Kevin Jones, (InterMind), Emiko Kezuka (Digital Vision Laboratories), Ora Lassila (Nokia Research Center), Andrew Layman (Microsoft), John McCarthy (Lawrence Berkeley National Laboratory), Michael Mealling (Network Solutions), Norbert Mikula (DataChannel), Eric Miller (OCLC), Frank Olken (Lawrence Berkeley National Laboratory), Sri Raghavan (Digital/Compaq), Lisa Rein (webMethods Inc.), Tsuyoshi Sakata (Digital Vision Laboratories), Leon Shklar (Pencom Web Works), David Singer (IBM), Wei (William) Song (SISU), Neel Sundaresan (IBM), Ralph Swick (W3C), Naohiko Uramoto (IBM), Charles Wicksteed (Reuters Ltd.), Misha Wolf (Reuters Ltd.)
The following is an outline of the main changes made to this specification, latest first, since the Last Call Working Draft of 23 January 2003 . See the Last Call issue tracking document for details of the specific issues raised regarding this specification.
An RDFS description of the <a href="http://www.w3.org/2001/sw/RDFCore/TR/WD-rdf-mt-20030117/#InterpVocab"> RDF vocabulary and <a href="http://www.w3.org/2001/sw/RDFCore/TR/WD-rdf-mt-20030117/"> RDFS vocabulary is given here in RDF/XML syntax. Please note that the namespace URI for the RDF Schema vocabulary could change in future versions of this specification. This RDF schema includes statements describing RDF resources originally introduced by the 1999 RDF Model and Syntax specification, as well as definitions for resources introduced in the RDF Core Schema vocabulary.
This RDF/XML is also available as a separate RDF/XML document ( rdfs-namespace.xml ). It is not currently published at the W3C RDF Schema namespace URI .
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"> <rdfs:Class rdf:about="http://www.w3.org/2000/01/rdf-schema#Resource"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/> <rdfs:label>Resource</rdfs:label> <rdfs:comment>The class resource, everything.</rdfs:comment> </rdfs:Class> <rdf:Property rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#type"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/> <rdfs:label>type</rdfs:label> <rdfs:comment>The subject is an instance of a class.</rdfs:comment> <rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Class"/> <rdfs:domain rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> </rdf:Property> <rdfs:Class rdf:about="http://www.w3.org/2000/01/rdf-schema#Class"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/> <rdfs:label>Class</rdfs:label> <rdfs:comment>The class of classes.</rdfs:comment> <rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> </rdfs:Class> <rdf:Property rdf:about="http://www.w3.org/2000/01/rdf-schema#subClassOf"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/> <rdfs:label>subClassOf</rdfs:label> <rdfs:comment>The subject is a subclass of a class.</rdfs:comment> <rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Class"/> <rdfs:domain rdf:resource="http://www.w3.org/2000/01/rdf-schema#Class"/> </rdf:Property> <rdf:Property rdf:about="http://www.w3.org/2000/01/rdf-schema#subPropertyOf"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/> <rdfs:label>subPropertyOf</rdfs:label> <rdfs:comment>The subject is a subproperty of a property.</rdfs:comment> <rdfs:range rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/> <rdfs:domain rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/> </rdf:Property> <rdfs:Class rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/> <rdfs:label>Property</rdfs:label> <rdfs:comment>The class of RDF properties.</rdfs:comment> <rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> </rdfs:Class> <rdf:Property rdf:about="http://www.w3.org/2000/01/rdf-schema#comment"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/> <rdfs:label>comment</rdfs:label> <rdfs:comment>A description of the subject resource.</rdfs:comment> <rdfs:domain rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> <rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Literal"/> </rdf:Property> <rdf:Property rdf:about="http://www.w3.org/2000/01/rdf-schema#label"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/> <rdfs:label>label</rdfs:label> <rdfs:comment>A human-readable name for the subject.</rdfs:comment> <rdfs:domain rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> <rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Literal"/> </rdf:Property> <rdf:Property rdf:about="http://www.w3.org/2000/01/rdf-schema#domain"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/> <rdfs:label>domain</rdfs:label> <rdfs:comment>A domain of the subject property.</rdfs:comment> <rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Class"/> <rdfs:domain rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/> </rdf:Property> <rdf:Property rdf:about="http://www.w3.org/2000/01/rdf-schema#range"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/> <rdfs:label>range</rdfs:label> <rdfs:comment>A range of the subject property.</rdfs:comment> <rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Class"/> <rdfs:domain rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/> </rdf:Property> <rdf:Property rdf:about="http://www.w3.org/2000/01/rdf-schema#seeAlso"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/> <rdfs:label>seeAlso</rdfs:label> <rdfs:comment>Further information about the subject resource.</rdfs:comment> <rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> <rdfs:domain rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> </rdf:Property> <rdf:Property rdf:about="http://www.w3.org/2000/01/rdf-schema#isDefinedBy"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/> <rdf:type rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/> <rdfs:subPropertyOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#seeAlso"/> <rdfs:label>isDefinedBy</rdfs:label> <rdfs:comment>The defininition of the subject resource.</rdfs:comment> <rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> <rdfs:domain rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> </rdf:Property> <rdfs:Class rdf:about="http://www.w3.org/2000/01/rdf-schema#Literal"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/> <rdfs:label>Literal</rdfs:label> <rdfs:comment>The class of literal values, eg. textual strings and integers.</rdfs:comment> </rdfs:Class> <rdfs:Class rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#Statement"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/> <rdfs:label>Statement</rdfs:label> <rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> <rdfs:comment>The class of RDF statements.</rdfs:comment> </rdfs:Class> <rdf:Property rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#subject"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/> <rdfs:label>subject</rdfs:label> <rdfs:comment>The subject of the subject RDF statement.</rdfs:comment> <rdfs:domain rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Statement"/> <rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> </rdf:Property> <rdf:Property rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/> <rdfs:label>predicate</rdfs:label> <rdfs:comment>The predicate of the subject RDF statement.</rdfs:comment> <rdfs:domain rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Statement"/> <rdfs:range rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/> </rdf:Property> <rdf:Property rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#object"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/> <rdfs:label>object</rdfs:label> <rdfs:comment>The object of the subject RDF statement.</rdfs:comment> <rdfs:domain rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Statement"/> <rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> </rdf:Property> <rdfs:Class rdf:about="http://www.w3.org/2000/01/rdf-schema#Container"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/> <rdfs:label>Container</rdfs:label> <rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> <rdfs:comment>The class of RDF containers.</rdfs:comment> </rdfs:Class> <rdfs:Class rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#Bag"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/> <rdfs:label>Bag</rdfs:label> <rdfs:comment>The class of unordered containers.</rdfs:comment> <rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Container"/> </rdfs:Class> <rdfs:Class rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#Seq"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/> <rdfs:label>Seq</rdfs:label> <rdfs:comment>The class of ordered containers.</rdfs:comment> <rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Container"/> </rdfs:Class> <rdfs:Class rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#Alt"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/> <rdfs:label>Alt</rdfs:label> <rdfs:comment>The class of containers of alternatives.</rdfs:comment> <rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Container"/> </rdfs:Class> <rdfs:Class rdf:about="http://www.w3.org/2000/01/rdf-schema#ContainerMembershipProperty"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/> <rdfs:label>ContainerMembershipProperty</rdfs:label> <rdfs:comment>The class of container membership properties, rdf:_1, rdf:_2, ..., all of which are sub-properties of 'member'.</rdfs:comment> <rdfs:subClassOf rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Property"/> </rdfs:Class> <rdf:Property rdf:about="http://www.w3.org/2000/01/rdf-schema#member"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/> <rdfs:label>member</rdfs:label> <rdfs:comment>A member of the subject resource.</rdfs:comment> <rdfs:domain rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> <rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> </rdf:Property> <rdf:Property rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#value"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/> <rdfs:label>value</rdfs:label> <rdfs:comment>Idiomatic property used for structured values.</rdfs:comment> <rdfs:domain rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> <rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> </rdf:Property> <!-- the following are new additions, Nov 2002 --> <rdfs:Class rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#List"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/> <rdfs:label>List</rdfs:label> <rdfs:comment>The class of RDF Lists.</rdfs:comment> </rdfs:Class> <rdf:List rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#nil"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/> <rdfs:label>nil</rdfs:label> <rdfs:comment>The empty list, with no items in it. If the rest of a list is nil then the list has no more items in it.</rdfs:comment> </rdf:List> <rdf:Property rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#first"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/> <rdfs:label>first</rdfs:label> <rdfs:comment>The first item in the subject RDF list.</rdfs:comment> <rdfs:domain rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#List"/> <rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> </rdf:Property> <rdf:Property rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#rest"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/> <rdfs:label>rest</rdfs:label> <rdfs:comment>The rest of the subject RDF list after the first item.</rdfs:comment> <rdfs:domain rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#List"/> <rdfs:range rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#List"/> </rdf:Property> <rdfs:Class rdf:about="http://www.w3.org/2000/01/rdf-schema#Datatype"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/> <rdfs:label>Datatype</rdfs:label> <rdfs:comment>The class of RDF datatypes.</rdfs:comment> <rdfs:subClassOf rdf:resource="http://www.w3.org/2000/01/rdf-schema#Class"/> </rdfs:Class> <rdfs:Datatype rdf:about="http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral"> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#"/> <rdfs:label>XMLLiteral</rdfs:label> <rdfs:comment>The class of XML literal values.</rdfs:comment> </rdfs:Datatype> <rdf:Description rdf:about="http://www.w3.org/2000/01/rdf-schema#"> <rdfs:seeAlso rdf:resource="http://www.w3.org/2000/01/rdf-schema-more"/> </rdf:Description> </rdf:RDF> |