W3C

SPARQL 1.1 Service Description

W3C Working Draft 05 January 2012

This version:
http://www.w3.org/TR/2012/WD-sparql11-service-description-20120105/
Latest version:
http://www.w3.org/TR/sparql11-service-description/
Previous version:
http://www.w3.org/TR/2011/WD-sparql11-service-description-20110512/
Editor:
Gregory Todd Williams, Rensselaer Polytechnic Institute <greg@evilfunhouse.com>

Abstract

This document describes SPARQL service description, a method for discovering, and vocabulary for describing SPARQL services made available via the SPARQL 1.1 Protocol for RDF [SPROT]. These descriptions provide a mechanism by which a client or end user can discover information about the SPARQL service such as supported extension functions and details about the available dataset.

Status of this Document

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 W3C technical reports index at http://www.w3.org/TR/.

This document is a Last Call Working Draft. Publication as a Last Call Working Draft indicates that the SPARQL Working Group believes it has addressed all substantive issues and that the document is stable. The Working Group expects to advance this specification to Recommendation Status.

The end date of the Last Call review period is 06 February 2012, i.e., comments on this working draft are due on or before this date.

Comments on this document should be sent to public-rdf-dawg-comments@w3.org, a mailing list with a public archive. Questions and comments about SPARQL that are not related to this specification, including extensions and features, can be discussed on the mailing list public-sparql-dev@w3.org, (public archive).

The SPARQL WG welcomes reports of implementations, sent to the comments address. If we gather sufficient evidence of interoperable implementations, the group may request to skip its Call for Implementations (Candidate Recommendation) drafts and have the next round of publications be Proposed Recommendations.

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.

The set of SPARQL documents comprises:

This document was produced by the SPARQL Working Group, which is part of the W3C Semantic Web Activity.

This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.

Since the publication of the previous working draft of this document, the primary changes are as follows.

Table of Contents

1 Introduction
    1.1 Terminology
2 Accessing a Service Description
3 Service Description Vocabulary
    3.1 SPARQL Service Description Namespace and OWL Ontology
    3.2 Properties
        3.2.1 sd:endpoint
        3.2.2 sd:feature
        3.2.3 sd:defaultEntailmentRegime
        3.2.4 sd:entailmentRegime
        3.2.5 sd:defaultSupportedEntailmentProfile
        3.2.6 sd:supportedEntailmentProfile
        3.2.7 sd:extensionFunction
        3.2.8 sd:extensionAggregate
        3.2.9 sd:languageExtension
        3.2.10 sd:supportedLanguage
        3.2.11 sd:propertyFeature
        3.2.12 sd:defaultDataset
        3.2.13 sd:availableGraphs
        3.2.14 sd:resultFormat
        3.2.15 sd:inputFormat
        3.2.16 sd:defaultGraph
        3.2.17 sd:namedGraph
        3.2.18 sd:name
        3.2.19 sd:graph
    3.3 Classes
        3.3.1 sd:Service
        3.3.2 sd:Feature
        3.3.3 sd:Language
        3.3.4 sd:Function
        3.3.5 sd:Aggregate
        3.3.6 sd:EntailmentRegime
        3.3.7 sd:EntailmentProfile
        3.3.8 sd:GraphCollection
        3.3.9 sd:Dataset
        3.3.10 sd:Graph
        3.3.11 sd:NamedGraph
    3.4 Instances
        3.4.1 sd:SPARQL10Query
        3.4.2 sd:SPARQL11Query
        3.4.3 sd:SPARQL11Update
        3.4.4 sd:DereferencesURIs
        3.4.5 sd:UnionDefaultGraph
        3.4.6 sd:RequiresDataset
        3.4.7 sd:EmptyGraphs
        3.4.8 sd:BasicFederatedQuery
        3.4.9 Other Instances
4 Example (Informative)
    4.1 RDF/XML Service Description
    4.2 Turtle Service Description
5 Conformance

Appendices

A References
    A.1 Normative References
    A.2 Other References
B CVS History


1 Introduction

A SPARQL service description lists the features of a SPARQL service made available via the SPARQL 1.1 Protocol for RDF [SPROT]. This document describes both a method for discovering a service description from a specific SPARQL service and an RDF schema for encoding such descriptions in RDF.

1.1 Terminology

When this document uses the words MUST, SHOULD and MAY, and the words appear as emphasized text, they must be interpreted as described in [RFC2119].

The following terms are also in use throughout this document:

SPARQL Service
Any implementation conforming to the SPARQL 1.1 Protocol for RDF (this document's use of "SPARQL Service" is the same as "SPARQL Protocol service" as defined in the SPARQL 1.1 Protocol) [SPROT]. A SPARQL service is commonly referred to as a "SPARQL endpoint".

2 Accessing a Service Description

SPARQL services made available via the SPARQL Protocol SHOULD return a service description document at the service endpoint when dereferenced using the HTTP GET operation. This service description MUST be made available in an RDF serialization, MAY be embedded in (X)HTML by way of RDFa [RDFA], and SHOULD use content negotiation [CONNEG] if available in other RDF representations.

3 Service Description Vocabulary

3.1 SPARQL Service Description Namespace and OWL Ontology

The SPARQL service description namespace IRI is:

http://www.w3.org/ns/sparql-service-description#

The prefix used in this document for this namespace is sd.

An RDF encoding of the Service Description ontology is available by HTTP content negotiation from the namespace IRI.

3.2 Properties

3.2.1 sd:endpoint

Relates an instance of sd:Service to a SPARQL endpoint that implements the SPARQL Protocol service [SPROT] for the service. The object of the sd:endpoint property is an IRI.

type:owl:InverseFunctionalProperty
domain:sd:Service

3.2.2 sd:feature

Relates an instance of sd:Service with a resource representing a supported feature.

domain:sd:Service
range:sd:Feature

3.2.3 sd:defaultEntailmentRegime

Relates an instance of sd:Service with a resource representing an entailment regime used for basic graph pattern matching. This property is intended for use when a single entailment regime by default applies to all graphs in the default dataset of the service. In situations where a different entailment regime applies to a specific graph in the dataset, the sd:entailmentRegime property should be used to indicate this fact in the description of that graph.

subPropertyOf:sd:feature
domain:sd:Service
range:sd:EntailmentRegime

3.2.4 sd:entailmentRegime

Relates a named graph description with a resource representing an entailment regime used for basic graph pattern matching over that graph.

domain:sd:NamedGraph
range:sd:EntailmentRegime

3.2.5 sd:defaultSupportedEntailmentProfile

Relates an instance of sd:Service with a resource representing a supported profile of the default entailment regime (as declared by sd:defaultEntailmentRegime). Entailment profiles are discussed more in SPARQL 1.1 Entailment Regimes [SPARQLENT].

Note that this specification does not make any conformance requirements on the compatibility of an advertised entailment profile with the advertised entailment regime in a service description. Providing a reasonable combination of values to the sd:entailmentRegime/sd:defaultEntailmentRegime and sd:supportedEntailmentProfile/sd:defaultSupportedEntailmentProfile properties is up to the creator of a service description.

subPropertyOf:sd:feature
domain:sd:Service
range:sd:EntailmentProfile

3.2.6 sd:supportedEntailmentProfile

Relates a named graph description with a resource representing a supported profile of the entailment regime (as declared by sd:entailmentRegime) used for basic graph pattern matching over that graph.

domain:sd:NamedGraph
range:sd:EntailmentProfile

3.2.7 sd:extensionFunction

Relates an instance of sd:Service to a function that may be used in a SPARQL SELECT expression or a FILTER, HAVING, GROUP BY, ORDER BY, or BIND clause.

subPropertyOf:sd:feature
domain:sd:Service
range:sd:Function

3.2.8 sd:extensionAggregate

Relates an instance of sd:Service to an aggregate that may be used in a SPARQL aggregate query (for instance in a HAVING clause or SELECT expression) besides the standard list of supported aggregates COUNT, SUM, MIN, MAX, AVG, GROUP_CONCAT, and SAMPLE.

subPropertyOf:sd:feature
domain:sd:Service
range:sd:Aggregate

3.2.9 sd:languageExtension

Relates an instance of sd:Service to a resource representing an implemented extension to the SPARQL Query or Update language.

subPropertyOf:sd:feature
domain:sd:Service
range:sd:Feature

3.2.10 sd:supportedLanguage

Relates an instance of sd:Service to a SPARQL language (e.g. Query and Update) that it implements.

subPropertyOf:sd:feature
domain:sd:Service
range:sd:Language

3.2.11 sd:propertyFeature

Relates an instance of sd:Service to a resource representing an implemented feature that extends the SPARQL Query or Update language and that is accessed by using the named property.

subPropertyOf:sd:feature
domain:sd:Service
range:sd:Feature

3.2.12 sd:defaultDataset

Relates an instance of sd:Service to a description of the default dataset available when no explicit dataset is specified in the query, update request or via protocol parameters.

type:owl:InverseFunctionalProperty
domain:sd:Service
range:sd:Dataset

3.2.13 sd:availableGraphs

Relates an instance of sd:Service to a description of the graphs that may be used in the construction of a dataset either via the SPARQL Protocol, with FROM/FROM NAMED clauses in a query, or with USING/USING NAMED in an update request.

domain:sd:Service
range:sd:GraphCollection

3.2.14 sd:resultFormat

Relates an instance of sd:Service to a format that is supported for serializing query results.

URIs for commonly used serialization formats are defined by Unique URIs for File Formats. For formats that do not have an existing URI, the <http://www.w3.org/ns/formats/media_type> and <http://www.w3.org/ns/formats/preferred_suffix> properties defined in that document SHOULD be used to describe the format.

domain:sd:Service
range:<http://www.w3.org/ns/formats/Format>

3.2.15 sd:inputFormat

Relates an instance of sd:Service to a format that is supported for parsing RDF input; for example, via a SPARQL 1.1 Update LOAD statement, or when URIs are dereferenced in FROM/FROM NAMED/USING/USING NAMED clauses (see also sd:DereferencesURIs below).

URIs for commonly used serialization formats are defined by Unique URIs for File Formats. For formats that do not have an existing URI, the <http://www.w3.org/ns/formats/media_type> and <http://www.w3.org/ns/formats/preferred_suffix> properties defined in that document SHOULD be used to describe the format.

domain:sd:Service
range:<http://www.w3.org/ns/formats/Format>

3.2.16 sd:defaultGraph

Relates an instance of sd:Dataset to the description of its default graph.

domain:sd:Dataset
range:sd:Graph

3.2.17 sd:namedGraph

Relates an instance of sd:GraphCollection (or its subclass sd:Dataset) to the description of one of its named graphs. The description of such a named graph MUST include the sd:name property and MAY include the sd:graph property.

domain:sd:GraphCollection
range:sd:NamedGraph

3.2.18 sd:name

Relates a named graph to the name by which it may be referenced in a FROM/FROM NAMED clause. The object of the sd:name property is an IRI.

domain:sd:NamedGraph

3.2.19 sd:graph

Relates a named graph to its graph description.

domain:sd:NamedGraph
range:sd:Graph

3.3 Classes

3.3.1 sd:Service

An instance of sd:Service represents a SPARQL service made available via the SPARQL Protocol.

type:rdfs:Class

3.3.2 sd:Feature

An instance of sd:Feature represents a feature of a SPARQL service. Specific types of features include functions, aggregates, languages, and entailment regimes and profiles. This document defines five instances of sd:Feature: sd:DereferencesURIs, sd:UnionDefaultGraph, sd:RequiresDataset, sd:EmptyGraphs, and sd:BasicFederatedQuery.

type:rdfs:Class

3.3.3 sd:Language

An instance of sd:Language represents one of the SPARQL languages, including specific configurations providing particular features or extensions. This document defines three instances of sd:Language: sd:SPARQL10Query, sd:SPARQL11Query, and sd:SPARQL11Update.

type:rdfs:Class
subClassOf:sd:Feature

3.3.4 sd:Function

An instance of sd:Function represents a function that may be used in a SPARQL SELECT expression or a FILTER, HAVING, GROUP BY, ORDER BY, or BIND clause.

type:rdfs:Class
subClassOf:sd:Feature

3.3.5 sd:Aggregate

An instance of sd:Aggregate represents an aggregate that may be used in a SPARQL aggregate query (for instance in a HAVING clause or SELECT expression) besides the standard list of supported aggregates COUNT, SUM, MIN, MAX, AVG, GROUP_CONCAT, and SAMPLE.

type:rdfs:Class
subClassOf:sd:Feature

3.3.6 sd:EntailmentRegime

An instance of sd:EntailmentRegime represents an entailment regime used in basic graph pattern matching (as described by SPARQL 1.1 Query Language). URIs for commonly used entailment regimes are defined by Unique URIs for Semantic Web Entailment Regimes [ENTAILMENT].

type:rdfs:Class
subClassOf:sd:Feature

3.3.7 sd:EntailmentProfile

An instance of sd:EntailmentProfile represents a profile of an entailment regime. An entailment profile MAY impose restrictions on what constitutes valid RDF with respect to entailment. URIs for commonly used entailment profiles are defined by Unique URIs for OWL 2 Profiles [OWL2PROF].

type:rdfs:Class
subClassOf:sd:Feature

3.3.8 sd:GraphCollection

An instance of sd:GraphCollection represents a collection of zero or more named graph descriptions. Each named graph description belonging to an sd:GraphCollection MUST be linked with the sd:namedGraph predicate.

type:rdfs:Class

3.3.9 sd:Dataset

An instance of sd:Dataset represents a RDF Dataset comprised of a default graph and zero or more named graphs.

The default graph of an sd:Dataset MUST be linked with the sd:defaultGraph predicate.

type:rdfs:Class
subClassOf:sd:GraphCollection

3.3.10 sd:Graph

An instance of sd:Graph represents the description of an RDF graph.

This document does not define properties with domain sd:Graph. Instead, such instances may be described using other appropriate vocabularies (see example below).

type:rdfs:Class

3.3.11 sd:NamedGraph

An instance of sd:NamedGraph represents a named graph having a name (via sd:name) and an optional graph description (via sd:graph).

type:rdfs:Class

3.4 Instances

3.4.1 sd:SPARQL10Query

sd:SPARQL10Query is an sd:Language representing the SPARQL 1.0 Query language [QUERY10].

type:sd:Language

3.4.2 sd:SPARQL11Query

sd:SPARQL11Query is an sd:Language representing the SPARQL 1.1 Query language [QUERY11].

type:sd:Language

3.4.3 sd:SPARQL11Update

sd:SPARQLUpdate is an sd:Language representing the SPARQL 1.1 Update language [UPDATE11].

type:sd:Language

3.4.4 sd:DereferencesURIs

sd:DereferencesURIs, when used as the object of the sd:feature property, indicates that a SPARQL service will dereference [AWWW] URIs used in FROM/FROM NAMED and USING/USING NAMED clauses and use the resulting RDF in the dataset during query evaluation.

type:sd:Feature

3.4.5 sd:UnionDefaultGraph

sd:UnionDefaultGraph, when used as the object of the sd:feature property, indicates that the default graph of the dataset used during query and update evaluation (when an explicit dataset is not specified) is comprised of the union of all the named graphs in that dataset.

type:sd:Feature

3.4.6 sd:RequiresDataset

sd:RequiresDataset, when used as the object of the sd:feature property, indicates that the SPARQL service requires an explicit dataset declaration (based on either FROM/FROM NAMED clauses in a query, USING/USING NAMED clauses in an update, or the appropriate SPARQL Protocol parameters).

type:sd:Feature

3.4.7 sd:EmptyGraphs

sd:EmptyGraphs, when used as the object of the sd:feature property, indicates that the underlying graph store supports empty graphs. A graph store that supports empty graphs MUST NOT remove graphs that are left empty after triples are removed from them. (See 3.1 Graph Update in SPARQL 1.1 Update.)

type:sd:Feature

3.4.8 sd:BasicFederatedQuery

sd:BasicFederatedQuery, when used as the object of the sd:feature property, indicates that the SPARQL service supports basic federated query using the SERVICE keyword as defined by SPARQL 1.1 Federated Query [SPARQLFED].

type:sd:Feature

3.4.9 Other Instances

Apart from the instances listed above, custom extensions and other documents may define further instance URIs usable within service descriptions; the following documents also list instance URIs that may be used with some of the properties defined in the previous sections:

4 Example (Informative)

The following HTTP traces illustrate the retrieval of a service description from the SPARQL service http://www.example/sparql/.

This RDF describes a SPARQL service available at the URL http://www.example/sparql/ that supports the SPARQL 1.1 Query language. The service will dereference URLs used in FROM/FROM NAMED clauses, supports both the RDF/XML and Turtle serialization formats, supports the http://example.org/Distance extension function, and has a dataset with a default graph and one named graph, both described using the voiD vocabulary [VOID]. The default graph contains 100 triples and supports RDFS entailment while the graph named http://www.example/named-graph contains 2000 triples and supports OWL2 RL entailment.

4.1 RDF/XML Service Description

Given the HTTP request:

GET /sparql/ HTTP/1.1
Host: www.example

the SPARQL service responds with an RDF/XML encoded service description (no content negotiation or RDFa encoding is used):

HTTP/1.1 200 OK
Date: Fri, 09 Oct 2009 17:31:12 GMT
Server: Apache/1.3.29 (Unix) PHP/4.3.4 DAV/1.0.3
Connection: close
Content-Type: application/rdf+xml

<?xml version="1.0" encoding="utf-8"?>
<rdf:RDF
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:sd="http://www.w3.org/ns/sparql-service-description#"
   xmlns:prof="http://www.w3.org/ns/owl-profile/"
   xmlns:scovo="http://purl.org/NET/scovo#"
   xmlns:void="http://rdfs.org/ns/void#">
  <sd:Service>
    <sd:endpoint rdf:resource="http://www.example/sparql/"/>
    <sd:supportedLanguage rdf:resource="http://www.w3.org/ns/sparql-service-description#SPARQL11Query"/>
    <sd:resultFormat rdf:resource="http://www.w3.org/ns/formats/RDF_XML"/>
    <sd:resultFormat rdf:resource="http://www.w3.org/ns/formats/Turtle"/>
    <sd:feature rdf:resource="http://www.w3.org/ns/sparql-service-description#DereferencesURIs"/>
    <sd:defaultEntailmentRegime rdf:resource="http://www.w3.org/ns/entailment/RDFS"/>
    <sd:extensionFunction>
      <sd:Function rdf:about="http://example.org/Distance"/>
    </sd:extensionFunction>
    <sd:defaultDataset>
      <sd:Dataset>
        <sd:defaultGraph>
          <sd:Graph>
            <void:triples rdf:datatype="http://www.w3.org/2001/XMLSchema#integer">100</void:triples>
          </sd:Graph>
        </sd:defaultGraph>
        <sd:namedGraph>
          <sd:NamedGraph>
            <sd:name rdf:resource="http://www.example/named-graph"/>
            <sd:entailmentRegime rdf:resource="http://www.w3.org/ns/entailment/OWL-RDF-Based"/>
            <sd:supportedEntailmentProfile rdf:resource="http://www.w3.org/ns/owl-profile/RL"/>
            <sd:graph>
              <sd:Graph>
                <void:triples rdf:datatype="http://www.w3.org/2001/XMLSchema#integer">2000</void:triples>
              </sd:Graph>
            </sd:graph>
          </sd:NamedGraph>
        </sd:namedGraph>
      </sd:Dataset>
    </sd:defaultDataset>
  </sd:Service>
</rdf:RDF>

4.2 Turtle Service Description

Given the HTTP request:

GET /sparql/ HTTP/1.1
Host: www.example
Accept: text/turtle

the SPARQL service responds with a Turtle [TURTLE] encoded service description:

HTTP/1.1 200 OK
Date: Fri, 09 Oct 2009 17:31:12 GMT
Server: Apache/1.3.29 (Unix) PHP/4.3.4 DAV/1.0.3
Connection: close
Content-Type: text/turtle

@prefix sd: <http://www.w3.org/ns/sparql-service-description#> .
@prefix ent: <http://www.w3.org/ns/entailment/> .
@prefix prof: <http://www.w3.org/ns/owl-profile/> .
@prefix scovo: <http://purl.org/NET/scovo#> .
@prefix void: <http://rdfs.org/ns/void#> .

[] a sd:Service ;
    sd:endpoint <http://www.example/sparql/> ;
    sd:supportedLanguage sd:SPARQL11Query ;
    sd:resultFormat <http://www.w3.org/ns/formats/RDF_XML>, <http://www.w3.org/ns/formats/Turtle> ;
    sd:extensionFunction <http://example.org/Distance> ;
    sd:feature sd:DereferencesURIs ;
    sd:defaultEntailmentRegime ent:RDFS ;
    sd:defaultDataset [
        a sd:Dataset ;
        sd:defaultGraph [
            a sd:Graph ;
            void:triples 100
        ] ;
        sd:namedGraph [
            a sd:NamedGraph ;
            sd:name <http://www.example/named-graph> ;
            sd:entailmentRegime ent:OWL-RDF-Based ;
            sd:supportedEntailmentProfile prof:RL ;
            sd:graph [
                a sd:Graph ;
                void:triples 2000
            ]
        ]
    ] .

<http://example.org/Distance> a sd:Function .

5 Conformance

A SPARQL service conformant with this specification:

  1. MUST return RDF content when the service endpoint URL is accessed as described in section 2 Accessing a Service Description.
  2. The RDF content returned from dereferencing a service endpoint URL <service-endpoint-URL> MUST include at least one triple matching:
    ?service sd:endpoint <service-endpoint-URL> .
  3. The RDF content returned MUST make use of the vocabulary defined in this document in accordance with the usage specified in section 3 Service Description Vocabulary.

A References

A.1 Normative References

[CONNEG]
Hypertext Transfer Protocol -- HTTP/1.1, Content Negotiation, Fielding, et al., IETF. June 1999. This document is http://www.w3.org/Protocols/rfc2616/rfc2616-sec12.html .
[RFC2119]
Key words for use in RFCs to Indicate Requirement Levels, S. Bradner, IETF. March 1997. This document is http://www.ietf.org/rfc/rfc2119.txt .
[QUERY10]
SPARQL Query Language for RDF, E. Prud'hommeaux and Andy Seaborne, Editors, W3C Recommendation, 15 January 2008. This document is http://www.w3.org/TR/rdf-sparql-query/ .
[QUERY11]
SPARQL 1.1 Query Language, Steve Harris and Andy Seaborne, Editors, W3C Editor's Draft, 14 October 2010. http://www.w3.org/TR/sparql11-query/ .
[SPROT]
SPARQL 1.1 Protocol for RDF, D. Charboneau, et al., Editors, W3C Editor's Draft, 26 January 2010, http://www.w3.org/2009/sparql/docs/protocol-1.1/Overview.xml .
[UPDATE11]
SPARQL 1.1 Update, S. Schenk, P. Gearon, and A. Passant, Editors, W3C Editor's Draft, 14 October 2010. http://www.w3.org/TR/sparql11-update/ .

A.2 Other References

[AWWW]
Architecture of the World Wide Web, Volume One, I. Jacobs and N. Walsh, Editors, W3C Recommendation, 15 December 2004. http://www.w3.org/TR/webarch/ .
[ENTAILMENT]
Unique URIs for Semantic Web Entailment Regimes
[FORMATS]
Unique URIs for File Formats
[OWL2PROF]
Unique URIs for OWL 2 Profiles
[RDFA]
RDFa in XHTML: Syntax and Processing, B. Adida, M. Birbeck, S. McCarron, and S. Pemberton, Editors, W3C Recommendation, 14 October 2008. http://www.w3.org/TR/rdfa-syntax/ .
[SPARQLENT]
SPARQL 1.1 Entailment Regimes, B. Glimm and C. Ogbuji, Editors, W3C Working Draft, 05 January 2012. http://www.w3.org/TR/sparql11-entailment/ .
[SPARQLFED]
SPARQL 1.1 Federated Query, E. Prud'hommeaux and C. Buil-Aranda, Editors, W3C Working Draft, 17 November 2011. http://www.w3.org/TR/2011/WD-sparql11-federated-query-20111117/ .
[TURTLE]
Turtle - Terse RDF Triple Language, D. Beckett, T. Berners-Lee, Editors, W3C Team Submission, 14 January 2008.
[VOID]
Describing Linked Datasets with the voiD Vocabulary, K. Alexander, R. Cyganiak, M. Hausenblas, and J. Zhao, Authors, W3C Interest Group Note, 3 March 2011, http://www.w3.org/TR/2011/NOTE-void-20110303/ . Latest version available at http://www.w3.org/TR/void/ .

B CVS History

$Log: Overview.html,v $
Revision 1.3  2017/10/02 10:46:21  denis
add fixup.js to old specs

Revision 1.2  2012/01/05 16:50:13  denis
fix

Revision 1.4  2012/01/05 16:19:04  apollere2
Re-added local.css

Revision 1.3  2012/01/05 03:45:56  apollere2
Fixed some references and links.

Revision 1.2  2012/01/05 03:30:42  apollere2
Adapted comments period to Feb 6th, as for the other docs.

Revision 1.1  2012/01/03 17:53:38  gwilliam
Pub prep.

Revision 1.22  2012/01/03 17:17:55  gwilliam
Fixed broken links.

Revision 1.79  2011/12/31 20:52:42  gwilliam
Updates for pub-rules process.

Revision 1.78  2011/12/19 17:07:09  gwilliam
Updated W3C links to TR space.
Removed useless cite tags from xmlspec.

Revision 1.77  2011/12/13 14:51:28  gwilliam
Added reference to ORDER BY clause in sd:extensionFunction and sd:Function sections.

Revision 1.76  2011/12/13 14:32:05  gwilliam
Updated changes since last publication.

Revision 1.75  2011/12/13 14:20:23  gwilliam
Added links to other SPARQL documents.

Revision 1.74  2011/12/07 05:12:41  gwilliam
Changes based on Chime's 2LC review <http://lists.w3.org/Archives/Public/public-rdf-dawg/2011OctDec/0309.html>

Revision 1.73  2011/12/07 03:39:50  gwilliam
More changes based on Axel's 2LC review.

Revision 1.72  2011/12/06 14:57:21  gwilliam
Fixed XML encoding bug.

Revision 1.71  2011/12/06 14:06:06  gwilliam
Changes based on Axel's 2LC review <http://lists.w3.org/Archives/Public/public-rdf-dawg/2011OctDec/0273.html>.

Revision 1.70  2011/11/04 16:05:48  gwilliam
Updated text to indicate that RDF is available by dereferencing the namespace IRI.

Revision 1.69  2011/10/18 14:23:28  gwilliam
Renamed sd:defaultDatasetDescription to sd:defaultDataset.
Renamed sd:availableGraphDescriptions to sd:availableGraphs.

Revision 1.68  2011/10/10 18:28:32  gwilliam
Fixed xml escaping in CVS Log.

Revision 1.67  2011/10/10 18:27:19  gwilliam
Changes based on DB-6:
Clarified that "accessing a service description" means with an HTTP GET.
s/a URI reference/an IRI/ in the description of the range of sd:endpoint and sd:name.
Added links and surrounded full URIs with <>.
Added note that no properties are defined for sd:Graph, but that it should be used with other appropriate vocabularies.

Revision 1.66  2011/08/16 17:06:35  gwilliam
Updated wording based on comments in DB-6.

Revision 1.65  2011/06/14 15:05:25  gwilliam
Added internal html links to sd properties, classes, and instances.

Revision 1.64  2011/05/30 12:41:47  gwilliam
Updated SPARQL links to /TR/ space.
Updated voiD link to URI of W3C NOTE.

Revision 1.63  2011/05/05 19:06:29  gwilliam
Updated links to new Protocol ED.

Revision 1.62  2011/05/05 18:56:06  gwilliam
Fixed old name for "Graph Store HTTP Protocol".

Revision 1.61  2011/05/03 18:01:47  gwilliam
Added description of changes since last WD.

Revision 1.60  2011/05/03 17:26:27  gwilliam
Added informative reference to Turtle team submission.

Revision 1.59  2011/05/03 17:16:02  gwilliam
Marked the 'Example' section as informative.

Revision 1.58  2011/05/03 15:26:10  gwilliam
Added use of entailment to example SD, and added an example of turtle serialization.

Revision 1.57  2011/05/03 14:05:41  gwilliam
Added sd:defaultSupportedEntailmentProfile.

Revision 1.56  2011/05/02 23:08:14  gwilliam
Updated terminology text linking to Protocol 1.1.
Reorderd entailment properties sections.
Tweaked example RDF/XML.

Revision 1.55  2011/04/19 19:44:00  gwilliam
Updated text and link from sd:endpoint to the Protocol document.

Revision 1.54  2011/04/07 05:28:37  gwilliam
Updated text for sd:EmptyGraphs with link to SPARQL 1.1 Update doc.

Revision 1.53  2011/04/05 15:58:51  gwilliam
Re-add comment about the range of sd:endpoint being a URI reference.

Revision 1.52  2011/04/05 15:32:35  gwilliam
Changed sd:url to sd:endpoint, and "service URL" to "service endpoint".

Revision 1.51  2011/03/10 16:26:11  gwilliam
Conformance now requires "at least one" matching triple in the SD RDF.

Revision 1.50  2011/03/01 05:39:01  gwilliam
Updated description of sd:url to indicate the range is a service endpoint.
Updated sd:defaultDatasetDescription to list type owl:InverseFunctionalProperty.
Updated sd:resultFormat and sd:inputFormat to discuss relevant formats: properties.
Updated description of sd:namedGraph to describe the use of sd:graph as optional.
Updated conformance section to require a triple using sd:url with the service URL.

Revision 1.49  2011/02/05 19:23:06  gwilliam
Added link to RDFa in section 2 Accessing a Service Description.
Added list of defined features in section 3.3.2 sd:Feature.
Added link to entailment document in section 3.2.4 sd:supportedEntailmentProfile.
Updated linked document name "SPARQL 1.1 RDF Dataset HTTP Protocol" in section 3.2.14 sd:inputFormat.
Added note on sd:GraphCollection subclass sd:Dataset in section 3.2.16 sd:namedGraph.
Added link to AWWW for use of "dereference" in section 3.4.4 sd:DereferencesURIs.
Changed use of ldodds:Distance function in example SD to ex:Distance.
Added bibliographic entries for SPARQL 1.1 Entailment Regimes, RDFa, and AWWW.
Added intra-document bibliographic citation links.

Revision 1.48  2011/01/25 16:01:51  gwilliam
Added note on range of sd:url as "URI reference".
Renamed "aggregate operation" to just "aggregate".

Revision 1.47  2011/01/24 21:06:48  gwilliam
Added ranges for sd:resultFormat and sd:inputFormat.
Added link to update document for discussion of "LOAD statement".

Revision 1.46  2011/01/23 04:00:31  gwilliam
QNames are now marked up with code tags.
Consistent capitalization of "service description".

Revision 1.45  2011/01/22 22:46:38  gwilliam
More pre-LC changes:
Added conformance section
Added more links into the query doc.
Fixed linking of title text in references section.

Revision 1.44  2011/01/22 22:00:12  gwilliam
Updates based on pre-LC reviews by NicoM and LeeF.

Revision 1.43  2011/01/13 02:51:33  gwilliam
Updated reference and link to extending BGP matching section of SPARQL 1.1 Query doc.

Revision 1.42  2010/11/23 16:14:38  gwilliam
Added sd:BasicFederatedQuery feature.

Revision 1.41  2010/10/31 02:59:14  gwilliam
Fixed stated rdfs:domain of sd:defaultGraph.

Revision 1.40  2010/10/05 15:28:02  gwilliam
Updated document to use styling from local.css.

Revision 1.39  2010/10/05 15:05:36  gwilliam
Punctuation fixes.

Revision 1.38  2010/10/05 14:51:25  gwilliam
Reformatted schema information for classes/instances with html tables.

Revision 1.37  2010/10/05 14:01:52  gwilliam
Reformatted schema information for properties with html tables.

Revision 1.36  2010/10/05 02:21:08  gwilliam
Reworded description of sd:Language.
Updated the description of changes made since last the previous working draft.

Revision 1.35  2010/09/24 20:04:20  gwilliam
Updated editor's comments.

Revision 1.34  2010/09/24 19:51:00  gwilliam
Formatting changes based on WG reviews.

Revision 1.33  2010/08/30 16:41:08  gwilliam
Added anchors for all div3 sections.

Revision 1.32  2010/08/30 01:17:02  gwilliam
Added cross-section links.
Typo fixes and rewording based on draft feedback.
Added sd:inputFormat.

Revision 1.31  2010/05/25 15:09:37  gwilliam
Updated the description of changes made since last the previous working draft.

Revision 1.30  2010/05/10 02:50:30  gwilliam
Added link for formats URIs.
Added rdfs:domain for sd:graph.
Fixed typos.

Revision 1.29  2010/05/04 15:21:49  gwilliam
Fixed formatting of sd:resultFormat definition.

Revision 1.28  2010/05/04 15:19:00  gwilliam
Added link to W3C list of Unique URIs for File Formats.

Revision 1.27  2010/04/27 02:05:08  gwilliam
Added sd:EmptyGraphs, fixed typo in sd:entailmentRegime.

Revision 1.26  2010/04/18 19:18:08  gwilliam
Renamed sd:named to sd:name.
Split Functions and Aggregates, and added sd:extensionAggregate.

Revision 1.25  2010/03/30 17:34:52  gwilliam
Updated based on F2F3 decisions including:
Added note about Unique URIs for serialization formats.
Added named graph rdfs:domain for sd:supportedEntailment.
Updated references section and added SPARQL Protocol reference.

Revision 1.24  2010/03/20 18:45:10  gwilliam
Added classes sd:GraphCollection, sd:Graph, and sd:NamedGraph.
Made sd:Dataset a subclass of sd:GraphCollection.
Updated list of sd:Language instances.
Added sd:RequiresDataset feature.
Added properties sd:propertyFeature, sd:resultFormat.
Made sd:namedGraph have domain of sd:GraphCollection and range of sd:NamedGraph.
Made sd:named have domain of sd:NamedGraph.

Revision 1.23  2010/01/22 00:57:56  apollere2
Changed anticipated pub date to 26

Revision 1.22  2010/01/21 22:06:15  apollere2
Added previous location.

Revision 1.21  2010/01/21 22:01:29  apollere2
changed date.

Revision 1.20  2010/01/06 02:42:35  gwilliam
Added missing entailment profiles link text.

Revision 1.19  2010/01/06 02:40:59  gwilliam
Added link to W3C defined entailment profiles.

Revision 1.18  2010/01/05 03:22:41  gwilliam
Updated class/property descriptions.
Updated summary of changes.
Added @@ comments for needed changes.

Revision 1.17  2010/01/02 01:15:12  gwilliam
Capitalized feature IRIs.
Added description of sd:Function.

Revision 1.16  2009/12/23 23:03:09  gwilliam
pluralization fix.
removed trailing slash on graph name IRI.
removed extra section markup in CVS History.

Revision 1.15  2009/12/18 21:01:34  gwilliam
Added entialment regimes link.
Added entailment profile class and properties.
Added sd:entailmentRegime.
Renamed supportedEntailment to defaultEntailmentRegime.

Revision 1.14  2009/12/18 19:57:08  gwilliam
Added sd:named and sd:graph properties.
Updated example RDF.

Revision 1.13  2009/12/15 05:44:13  gwilliam
summary of changes since fpwd.
replaced more uses of sd:defaultDataset.

Revision 1.12  2009/12/15 05:03:07  gwilliam
Renamed defaultDataset to defaultDatasetDescription.

Revision 1.11  2009/12/01 04:58:49  gwilliam
Added feature IRIs and updated datase description terms per 2009-11-24 telecon.

Revision 1.10  2009/12/01 04:07:02  gwilliam
Added sd:Dataset class, description of sd:SPARQLQuery and sd:SPARQLUpdate, and
fixed whitespace formatting in CVS Log.

Revision 1.9  2009/10/21 03:29:49  lfeigenb
pubrules fixes

Revision 1.8  2009/10/21 03:19:15  lfeigenb
publication prep

Revision 1.7  2009/10/20 20:47:23  lfeigenb
validation errors

Revision 1.6  2009/10/20 19:45:51  lfeigenb
small fixes for naming and cleanup

Revision 1.5  2009/10/20 18:03:06  lfeigenb
move to using the shared XML spec materials

Revision 1.4  2009/10/20 15:53:20  lfeigenb
updated NS URI as per Oct-20 meeting

Revision 1.3  2009/10/20 14:25:47  gwilliam
Fixed base.uri.
Commented out TURTLE reference.

Revision 1.2  2009/10/20 13:59:34  gwilliam
Removed duplicate namespace section.

Revision 1.1  2009/10/20 04:21:12  gwilliam
CREATED