[contents]


Abstract

The identification of resources on the Web by a Uniform Resource Identifier (URI) alone may not be sufficient, as other factors such as HTTP content negotiation might come into play. This issue is particularly significant for quality assurance testing, conformance claims, and reporting languages like the W3C Evaluation And Report Language (EARL). This document provides a representation of the HTTP vocabulary in the Resource Description Framework (RDF), to allow quality assurance tools to record the HTTP headers that have been exchanged between a client and a server. The RDF terms defined by this document represent the core HTTP specification defined by RFC 2616, as well as additional HTTP headers registered by the Internet Assigned Numbers Authority (IANA). These terms can also be used to record HTTPS exchanges.

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 2 May 2011 Editors Draft of HTTP Vocabulary in RDF 1.0 is an update of the previous HTTP Vocabulary in RDF Working Draft of 29 October 2009, and it incorporates all comments received since. This document is part of the W3C Evaluation And Report Language (EARL) but can be reused in other contexts too. This document is intended to be published and maintained as a W3C Working Group Note after review and refinement.

The Evaluation and Repair Tools Working Group (ERT WG) believes it has addressed all issues brought forth through previous Working Draft iterations. The Working Group encourages feedback about this document, HTTP Vocabulary in RDF 1.0, by developers and researchers who have interest in software-supported evaluation and validation of websites, and by developers and researchers who have interest in Semantic Web technologies for content description, annotation, and adaptation. In particular, feedback from the groups involved in the W3C Semantic Web Activity, especially the Semantic Web Coordination Group, the Semantic Web Deployment Working Group, and the Semantic Web Interest Group would be greatly appreciated.

Please send comments on this HTTP Vocabulary in RDF 1.0 document by @@@ to public-earl10-comments@w3.org (publicly visible mailing list archive).

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.

This document has been produced by the Evaluation and Repair Tools Working Group (ERT WG) as part of the Web Accessibility Initiative (WAI) Technical Activity.

This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. The group does not expect this document to become a W3C Recommendation. 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.


Table of Contents

  1. Introduction
  2. Classes
  3. Properties

Appendices

  1. A practical Example
  2. Terms
  3. References
  4. Document Changes

1 Introduction

This document defines a representation of the Hypertext Transfer Protocol (HTTP) using the Resource Description Framework (RDF). It defines a collection of RDF classes and properties that represent the HTTP vocabulary as defined by the HTTP specification [RFC2616]. These RDF terms can be used to record HTTP or secure HTTP request and response messages in RDF format, such as by automated Web accessibility evaluation tools that want to describe Web resources, including the various headers exchanged between the client and server during content negotiation. More usage examples for these terms are described in section 1.2 Use Cases.

Note: The version 1.0 specifies the version of the HTTP Vocabulary in RDF document and not the version of HTTP. The vocabulary defined in this specification is usable for HTTP versions up to 1.1.

This document is not intended to be a clarification or extension of the different concepts of the HTTP specification. The HTTP specification is defined by a series of Request for Comments (RFC) publications and other documentation, including [RFC 2616] and [RFC 4229]. These are listed in Appendix C: References.

Additionally this document assumes the following background knowledge:

The terms defined by this document can be used as part of the W3C Evaluation And Report Language (EARL) and in other contexts too. Developer Guide for Evaluation and Report Language (EARL) 1.0 explains how to implement and use EARL, including conformance requirements for software tools.

By default, the vocabulary introduced by this document uses names starting with upper-case letters for classes and names starting with lower-case letters for properties. The keywords must, required, recommended, should, may, and optional are used in accordance with [RFC2119].

1.1 Namespaces

The RDF representation of the HTTP vocabulary defined by this document uses the namespace http://www.w3.org/2011/http#. The prefix http is used throughout this document to denote this namespace. Table 1 presents the namespaces used by this document. The prefix notation presents the typical conventions used in the Web and in this document to denote a given namespace, and can be freely modified. Table 2 presents additional RDF data used by this document.

Table 1: namespaces used by this document.
Namespace prefix Namespace URI Description
http http://www.w3.org/2011/http# Namespace for the core terms of HTTP vocabulary in RDF.
cnt http://www.w3.org/2011/content# Namespace for Representing Content in RDF [Content-in-RDF].
dct http://purl.org/dc/terms/ Namespace for the Dublin Core Metadata Terms.
owl http://www.w3.org/2002/07/owl# Namespace for OWL [OWL].
rdf http://www.w3.org/1999/02/22-rdf-syntax-ns# Namespace for RDF [RDF].
Table 2: RDF data used by this document.
URI Description
http://www.w3.org/2011/http-headers HTTP headers as registered by the IANA (see [RFC4229], [Permanent Headers], and [Provisional Headers]).
http://www.w3.org/2011/http-methods HTTP methods for requests.
http://www.w3.org/2011/http-statusCodes HTTP status codes for responses.

1.2 Use Cases

The following (non-exhaustive) list of use cases aims to highlight some of the different usages of the terms provided by this document:

Reporting Test Results
When Web resources are tested, for example for accessibility or other quality assurance testing, it may be significant to record the exact headers exchanged between the server and the client during the testing. Without a record of the exchanged headers, it may not be possible to re-identify the exact resource (or representation of the resource) that has been tested. The terms provided by this document allow quality assurance tools to record the HTTP exchange between a client and a server, for example to record the POST parameters or the headers used during content negotiation. The terms provided by this document can be used in combination with the W3C Evaluation And Report Language (EARL) [EARL].
Precising Conformance Claims
Conformance claims that are made about a Web resource or group of Web resource, are sometimes only applicable under certain constraints. For example, conformance of a Web site to the W3C Web Content Accessibility Guidelines (WCAG) [WCAG], may only be applicable for a certain language of the Web site that is using language negotiation. When providing machine-readable conformance claims, for example using the W3C Protocol for Describing Web Resources (POWDER): Description Resources [POWDER-DR], it is important to precise any such constraints that may apply.
Debugging Web Applications
Web applications using client-side scripting such as AJAX may exchange additional HTTP messages with the server without using a different URI. In order to debug such Web applications, it must be possible to reconstruct the exact history of the states through which the Web application passed. Web authoring tools that are designed to develop and debug Web applications could use the terms provided by this document to record the exact HTTP messages exchanged between a client and a server. This information could be provided to the developer as a log to help debug errors in the Web application.
Indexing Information Resources
When indexing RDF information resources that are available through the HTTP protocol (also called "scuttering" in Semantic Web parlance), it is often useful to record information about the HTTP request and response messages that were exchanged, along with the data for later use. In some instances, different representations of the RDF information may be retrieved from the server depending on the HTTP headers and parameters exchanged. The terms provided by this document can be used to supplement the collected data with the HTTP messages as part of a comprehensive indexing repository.

1.3 Limitations

There are also notable schema limitations in regard to security and privacy since the content recorded by this vocabulary could potentially contain sensitive information, for example authentication information in HTTP headers or other information (login user name, passwords, and so on) within the body of the message. Since the schema of this document is limited to terms defined by the HTTP vocabulary, security and privacy considerations need to be made at the application level. For example, certain parts of the data may be restricted to appropriate user permissions or obfuscated.

2 Classes

This section defines RDF classes for the HTTP 1.1 specification according to [RFC2616].

2.1 Connection Class

A connection that is used for the HTTP transfer.

Related Properties

Examples

Example 2.1: A Connection resource.

<http:Connection rdf:ID="conn">
  <http:connectionAuthority>www.example.org:80</http:connectionAuthority>
  <http:requests rdf:parseType="Collection">
    <http:Request rdf:ID="req0"/>
    <http:Request rdf:ID="req1"/>
  </http:requests>
</http:Connection>

2.2 Message Class

An HTTP message.

Related Properties

It may be appropriate to provide additional information about the Message by using the following from external vocabularies:

dct:date external link
Message date (see the usage of this property in requests and responses).

Examples

Example 2.2: A Message resource.

<http:Message rdf:ID="mess0">
  <http:httpVersion>1.1</http:httpVersion>
  <dct:date>2007-09-13</dct:date>
  <http:headers rdf:parseType="Collection">
    <http:MessageHeader rdf:ID="mh0"/>
    <http:MessageHeader rdf:ID="mh1"/>
  </http:headers>
  <http:body>
    <cnt:Content rdf:ID="cont0"/>
  </http:body>
</http:Message>

There are two subclasses from the http:Message class: http:Request and http:Response.

2.2.1 Request Class

An HTTP request. The http:Request class is a subclass of the http:Message class.

Related Properties

The dct:date property when used in a Request resource represents the date the request was sent by the client.

Examples

Example 2.3: A Request resource.

<http:Request rdf:ID="reqs0">
  <http:absolutePath>/</http:absolutePath>
  <http:methodName>GET</http:methodName>
  <http:mthd rdf:resource="http://www.w3.org/2011/http-methods#GET"/>
  <http:resp rdf:resource="#resp0"/>
  <dct:date>2007-09-13</dct:date>
  <http:httpVersion>1.1</http:httpVersion>
  <http:headers rdf:parseType="Collection">
    <http:MessageHeader rdf:about="#mh0"/>
    <http:MessageHeader rdf:about="#mh1"/>
  </http:headers>
</http:Request>

2.2.2 Response Class

An HTTP response. The http:Response class is a subclass of the http:Message class.

Related Properties

The dct:date property when used in a Response resource represents the date the response was received by the client.

Examples

Example 2.4: A Response resource.

<http:Response rdf:ID="resp0">
  <http:httpVersion>1.1</http:httpVersion>
  <dct:date>2008-01-11</dct:date>
  <http:statusCodeValue>200</http:statusCodeValue>
  <http:sc rdf:resource="http://www.w3.org/2011/http-statusCodes#OK"/>
  <http:headers rdf:parseType="Collection">
    <http:MessageHeader rdf:about="#mh2"/>
    <http:MessageHeader rdf:about="#mh3"/>
  </http:headers>
  <http:body>
    <cnt:Content rdf:ID="cont0"/>
  </http:body>
</http:Response>

2.3 MessageHeader Class

A header in an HTTP message.

Related Properties

Examples

Example 2.5: A MessageHeader resource.

<http:MessageHeader rdf:ID="mh0">
  <http:fieldValue>text/html, image/png, image/gif;q=0.8</http:fieldValue>
  <http:fieldName>Accept</http:fieldName>
  <http:hdrName rdf:resource="http://www.w3.org/2011/http-headers#accept"/>
  <http:headerElements rdf:parseType="Collection">
    <http:HeaderElement rdf:about="#he0"/>
    <http:HeaderElement rdf:about="#he1"/>
    <http:HeaderElement rdf:about="#he2"/>
  </http:headerElements>
</http:MessageHeader>

2.3.1 GeneralHeader Class

A general header in an HTTP message. The http:GeneralHeader class is a subclass of the http:MessageHeader class.

Related Properties

Examples

Example 2.6: A GeneralHeader resource.

<http:GeneralHeader rdf:ID="gh0">
  <http:fieldValue>chunked</http:fieldValue>
  <http:fieldName>Transfer-Encoding</http:fieldName>
  <http:hdrName rdf:resource="http://www.w3.org/2011/http-headers#transfer-encoding"/>
</http:GeneralHeader>

2.3.2 RequestHeader Class

A header in an HTTP request message. The http:RequestHeader class is a subclass of the http:MessageHeader class.

Related Properties

Examples

Example 2.7: A RequestHeader resource.

<http:RequestHeader rdf:ID="rh0">
  <http:fieldValue>text/html</http:fieldValue>
  <http:fieldName>Accept</http:fieldName>
  <http:hdrName rdf:resource="http://www.w3.org/2011/http-headers#accept"/>
</http:RequestHeader>

2.3.3 ResponseHeader Class

A header in an HTTP response message. The http:ResponseHeader class is a subclass of the http:MessageHeader class.

Related Properties

Examples

Example 2.8: A ResponseHeader resource.

<http:ResponseHeader rdf:ID="reh0">
  <http:fieldValue>bytes</http:fieldValue>
  <http:fieldName>Accept-Ranges</http:fieldName>
  <http:hdrName rdf:resource="http://www.w3.org/2011/http-headers#accept-ranges"/>
</http:ResponseHeader>

2.4 EntityHeader Class

An entity header in an HTTP message. The http:EntityHeader class is a subclass of the http:MessageHeader class.

Related Properties

Examples

Example 2.9: A EntityHeader resource.

<http:EntityHeader rdf:ID="eh0">
  <http:fieldValue>3495</http:fieldValue>
  <http:fieldName>Content-Length</http:fieldName>
  <http:hdrName rdf:resource="http://www.w3.org/2011/http-headers#content-length"/>
</http:EntityHeader>

2.5 HeaderElement Class

An element in a header value, if a Message Header value can be decomposed into several parts.

Related Properties

Examples

Example 2.10: A HeaderElement resource.

<http:HeaderElement rdf:ID="he0">
  <http:elementName>image/gif</http:elementName>
  <http:params rdf:parseType="Collection">
    <http:Parameter rdf:ID="param0"/>
  </http:params>
</http:HeaderElement>

2.6 Parameter Class

A parameter in a Header Element.

Related Properties

Examples

Example 2.11: A Parameter resource.

<http:Parameter rdf:ID="param0">
  <http:paramName>q</http:paramName>
  <http:paramValue>0.8</http:paramValue>
</http:Parameter>

2.7 Method Class

The HTTP 1.1 specification defines eight methods: OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, CONNECT. Additionally [RFC5789] defines the PATCH method. The RDF graph available in RDF/XML at http://www.w3.org/2011/http-methods provides http:Method resources for each of these to be used as objects for the http:mthd property. A resource of type http:Method represents the name of a method used with HTTP.

Related Properties

2.8 StatusCode Class

[HTTP Status Codes] is a registry for status codes too be used in HTTP. The RDF graph available in RDF/XML at http://www.w3.org/2011/http-statusCodes provides http:StatusCode resources for each of these to be used as objects for the http:sc property. A resource of type http:StatusCode represents a status code.

Related Properties

2.9 HeaderName Class

Header names to be used in HTTP are registered by the IANA (see [RFC4229], [Permanent Headers], and [Provisional Headers]). The RDF graph available in RDF/XML at http://www.w3.org/2011/http-headers provides http:HeaderName resources for each of these to be used as objects for the http:hdrName property. A resource of type http:HeaderName represents the name of a header used with HTTP.

Related Properties

Properties defined by this document:

3 Properties

This section defines RDF properties for the HTTP 1.1 specification according to [RFC2616].

3.1 body Property

This property relates a resource object of the type Message to a resource object of the type cnt:Content or a subclass thereof to be the Message's entity body as defined in [RFC2616]. HTTP bodies are series of bytes. Thus for the resource object, it is appropriate to point to a cnt:ContentAsBase64 resource (see [Content-in-RDF] for more information on content representations using the Resource Desription Framework (RDF)).

Domain:
http:Message
Range:
cnt:ContentAsBase64 external link

Examples

Example 3.1: The entity body of a message.

<http:Message rdf:ID="mess0">
    <http:body>
      <cnt:ContentAsBase64 rdf:ID="cont0-bin"/>
    </http:body>
  </http:Message>

3.2 connectionAuthority Property

Connection authority: server, host and port for a connection.

Domain:
http:Connection
Range:
Literal

3.3 elementName Property

Header element name (Literal).

Domain:
http:HeaderElement
Range:
Literal

3.4 elementValue Property

Header element value (Literal).

Domain:
http:HeaderElement
Range:
Literal

3.5 fieldName Property

Header name (Literal).

Domain:
http:MessageHeader
Range:
Literal

3.6 fieldValue Property

Header value (Literal).

Domain:
http:MessageHeader
Range:
Literal

3.7 headers Property

HTTP headers sent with the message.

Domain:
http:Message
Range:
unspecified

3.8 headerElements Property

Header value elements.

Domain:
http:MessageHeader
Range:
unspecified

3.9 hdrName Property

This property relates a resource of type http:MessageHeader to a resource of type http:HeaderName.

Domain:
http:MessageHeader
Range:
http:HeaderName

3.10 httpVersion Property

Property representing the HTTP version number as a Literal (the format is 'digit.digit').

Domain:
http:Message
Range:
Literal

3.11 mthd Property

HTTP method.

Domain:
http:Request
Range:
http:Method

3.12 methodName Property

HTTP method name (Literal).

Domain:
http:Request
Range:
Literal

3.13 params Property

Header element parameters.

Domain:
http:HeaderElement
Range:
unspecified

3.14 paramName Property

Parameter name.

Domain:
http:Parameter
Range:
Literal

3.15 paramValue Property

Parameter value.

Domain:
http:Parameter
Range:
Literal

3.16 reasonPhrase Property

Reason phrase sent by the server.

Domain:
http:Response
Range:
Literal

3.17 requests Property

HTTP requests sent via the connection.

Domain:
http:Connection
Range:
unspecified

3.18 requestURI Property

The request URI as specified in section 5.1.2 of [RFC2616]. This vocabulary defines the following sub-properties:

Domain:
http:Request
Range:
Literal

Examples

Example 3.2: The use of the requestURI property.

<http:Request>
  <http:methodName>OPTIONS</http:methodName>
  <http:requestURI>*</http:requestURI>
  ...
</http:Request>

3.18.1 absoluteURI Property

Request URI that is an absolute URI.

Examples

Example 3.3: The use of the absoluteURI property.

<http:Request>
  <http:methodName>GET</http:methodName>
  <http:absoluteURI>http://www.example.org:80/foo/bar</http:absoluteURI>
  ...
</http:Request>

3.18.2 absolutePath Property

Request URI that is an absolute path.

Examples

Example 3.4: The use of the absolutePath property.

<http:Request>
  <http:methodName>GET</http:methodName>
  <http:absolutePath>/foo/bar</http:absolutePath>
  ...
</http:Request>

3.18.3 authority Property

Request URI that is an authority.

Examples

Example 3.5: The use of the authority property.

<http:Request>
  <http:methodName>CONNECT</http:methodName>
  <http:authority>www.example.org:80</http:authority>
  ...
</http:Request>

3.19 resp Property

This property relates a resource of type http:Request to a resource of type http:Response.

Domain:
http:Request
Range:
http:Response

3.20 sc Property

This property relates a resource of type http:Response to a resource of type http:StatusCode.

Domain:
http:Response
Range:
http:StatusCode

3.21 statusCodeNumber Property

The status code value (integer) corresponding to the standardized status code value.

Domain:
http:StatusCode
Range:
http://www.w3.org/2001/XMLSchema#int

3.22 statusCodeValue Property

The actual status code value sent by the server (Literal).

Domain:
http:Response
Range:
Literal

Appendix A: A practical Example

The following example shows an RDF/XML representation of an HTTP request and response pair.

Scenario Description

A client sends two requests to a server at www.example.org port 80 via HTTP 1.1 GET. With each request, it sends request headers. The first request is for a resource in the document root (/), the second for a resource at /image. While handling the second request the server performs content negotiation respecting the request's Accept header and so sends a PNG image. This is indicated by the response's Vary header.

Resulting RDF/XML

<?xml version="1.0" encoding="utf-8"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
  xmlns:http="http://www.w3.org/2011/http#"
  xmlns:cnt="http://www.w3.org/2011/content#"
  xmlns:dct="http://purl.org/dc/terms/">

  <http:Connection rdf:ID="conn">
    <http:connectionAuthority>www.example.org:80</http:connectionAuthority>
    <http:requests rdf:parseType="Collection">
      <http:Request rdf:about="#req0"/>
      <http:Request rdf:about="#req1"/>
    </http:requests>
  </http:Connection>

  <http:Request rdf:about="#req0">
    <http:httpVersion>1.1</http:httpVersion>
    <http:methodName>GET</http:methodName>
    <http:mthd rdf:resource="http://www.w3.org/2011/http-methods#GET"/>
    <http:absolutePath>/</http:absolutePath>
    <http:headers rdf:parseType="Collection">
      <http:RequestHeader>
        <http:fieldName>Host</http:fieldName>
        <http:hdrName rdf:resource="http://www.w3.org/2011/http-headers#host"/>
        <http:fieldValue>www.example.org</http:fieldValue>
      </http:RequestHeader>
      <http:RequestHeader>
        <http:fieldName>User-Agent</http:fieldName>
        <http:hdrName rdf:resource="http://www.w3.org/2011/http-headers#user-agent"/>
        <http:fieldValue>My User Agent</http:fieldValue>
      </http:RequestHeader>
      <http:RequestHeader>
        <http:fieldName>Accept</http:fieldName>
        <http:hdrName rdf:resource="http://www.w3.org/2011/http-headers#accept"/>
        <http:fieldValue>text/html, image/png, image/gif;q=0.8</http:fieldValue>
        <http:headerElements rdf:parseType="Collection">
          <http:HeaderElement>
            <http:elementName>text/html</http:elementName>
          </http:HeaderElement>
          <http:HeaderElement>
            <http:elementName>image/png</http:elementName>
          </http:HeaderElement>
          <http:HeaderElement>
            <http:elementName>image/gif</http:elementName>
            <http:params rdf:parseType="Collection">
              <http:Parameter>
                <http:paramName>q</http:paramName>
                <http:paramValue>0.8</http:paramValue>
              </http:Parameter>
            </http:params>
          </http:HeaderElement>
        </http:headerElements>
      </http:RequestHeader>
    </http:headers>
    <http:resp rdf:resource="#resp0"/>
  </http:Request>

  <http:Request rdf:about="#req1">
    <http:httpVersion>1.1</http:httpVersion>
    <http:methodName>GET</http:methodName>
    <http:mthd rdf:resource="http://www.w3.org/2011/http-methods#GET"/>
    <http:absolutePath>/image</http:absolutePath>
    <http:headers rdf:parseType="Collection">
      <http:RequestHeader>
        <http:fieldName>Host</http:fieldName>
        <http:hdrName rdf:resource="http://www.w3.org/2011/http-headers#host"/>
        <http:fieldValue>www.example.org</http:fieldValue>
      </http:RequestHeader>
      <http:RequestHeader>
        <http:fieldName>User-Agent</http:fieldName>
        <http:hdrName rdf:resource="http://www.w3.org/2011/http-headers#user-agent"/>
        <http:fieldValue>My User Agent</http:fieldValue>
      </http:RequestHeader>
      <http:RequestHeader>
        <http:fieldName>Accept</http:fieldName>
        <http:hdrName rdf:resource="http://www.w3.org/2011/http-headers#accept"/>
        <http:fieldValue>image/png, image/gif;q=0.8</http:fieldValue>
        <http:headerElements rdf:parseType="Collection">
          <http:HeaderElement>
            <http:elementName>image/png</http:elementName>
          </http:HeaderElement>
          <http:HeaderElement>
            <http:elementName>image/gif</http:elementName>
            <http:params rdf:parseType="Collection">
              <http:Parameter>
                <http:paramName>q</http:paramName>
                <http:paramValue>0.8</http:paramValue>
              </http:Parameter>
            </http:params>
          </http:HeaderElement>
        </http:headerElements>
      </http:RequestHeader>
    </http:headers>
    <http:resp rdf:resource="#resp1"/>
  </http:Request>

  <http:Response rdf:ID="resp0">
    <http:httpVersion>1.1</http:httpVersion>
    <http:statusCodeValue>200</http:statusCodeValue>
    <http:sc rdf:resource="http://www.w3.org/2011/http-statusCodes#OK"/>
    <http:reasonPhrase>OK</http:reasonPhrase>
    <http:headers rdf:parseType="Collection">
      <http:GeneralHeader>
        <http:fieldName>Date</http:fieldName>
        <http:hdrName rdf:resource="http://www.w3.org/2011/http-headers#date"/>
        <http:fieldValue>.......</http:fieldValue>
      </http:GeneralHeader>
      <http:EntityHeader>
        <http:fieldName>Content-Type</http:fieldName>
        <http:hdrName rdf:resource="http://www.w3.org/2011/http-headers#content-type"/>
        <http:fieldValue>text/html; charset=utf-8</http:fieldValue>
        <http:headerElements rdf:parseType="Collection">
          <http:HeaderElement>
            <http:elementName>text/html</http:elementName>
            <http:params rdf:parseType="Collection">
              <http:Parameter>
                <http:paramName>charset</http:paramName>
                <http:paramValue>utf-8</http:paramValue>
              </http:Parameter>
            </http:params>
          </http:HeaderElement>
        </http:headerElements>
      </http:EntityHeader>
    </http:headers>
    <http:body>
      <cnt:ContentAsBase64 rdf:ID="cont0-bin">
        <cnt:bytes rdf:datatype="http://www.w3.org/2001/XMLSchema#base64Binary">ajrq9qguojbglj48z..........</cnt:bytes>
        <dct:isFormatOf rdf:resource="http://www.example.org/"/>
      </cnt:ContentAsBase64>
    </http:body>
  </http:Response>

  <http:Response rdf:ID="resp1">
    <http:httpVersion>1.1</http:httpVersion>
    <http:statusCodeValue>200</http:statusCodeValue>
    <http:sc rdf:resource="http://www.w3.org/2011/http-statusCodes#OK"/>
    <http:reasonPhrase>OK</http:reasonPhrase>
    <http:headers rdf:parseType="Collection">
      <http:MessageHeader>
        <http:fieldName>Date</http:fieldName>
        <http:hdrName rdf:resource="http://www.w3.org/2011/http-headers#date"/>
        <http:fieldValue>.......</http:fieldValue>
      </http:MessageHeader>
      <http:MessageHeader>
        <http:fieldName>Content-Type</http:fieldName>
        <http:hdrName rdf:resource="http://www.w3.org/2011/http-headers#content-type"/>
        <http:fieldValue>image/png</http:fieldValue>
      </http:MessageHeader>
      <http:MessageHeader>
        <http:fieldName>Vary</http:fieldName>
        <http:hdrName rdf:resource="http://www.w3.org/2011/http-headers#vary"/>
        <http:fieldValue>accept</http:fieldValue>
        <http:headerElements rdf:parseType="Collection">
          <http:HeaderElement>
            <http:elementName>accept</http:elementName>
          </http:HeaderElement>
        </http:headerElements>
      </http:MessageHeader>
    </http:headers>
    <http:body>
      <cnt:ContentAsBase64>
        <cnt:bytes rdf:datatype="http://www.w3.org/2001/XMLSchema#base64Binary">qouh3908t38hohfrf..........</cnt:bytes>
        <dct:isFormatOf rdf:resource="http://www.example.org/image"/>
      </cnt:ContentAsBase64>
    </http:body>
  </http:Response>

</rdf:RDF>

Appendix B: Terms

The following terms are defined by this specification:

Classes

Classes in the HTTP-in-RDF namespace
Class name Label Comment Refinements Related properties
http:Connection Connection A connection used for HTTP transfer. - http:connectionAuthority, http:requests
http:EntityHeader Entity Header An entity header in an HTTP message. - http:fieldName, http:fieldValue, http:hdrName, http:headerElements
http:GeneralHeader General Header A general header in an HTTP message. - http:fieldName, http:fieldValue, http:hdrName, http:headerElements
http:HeaderElement Header Element A part of a deconstructed header value. - http:elementName, http:elementValue, http:params
http:HeaderName Header Name The header name. -
http:Message Message An HTTP message. http:Request, http:Response http:httpVersion, dct:date, http:body, http:headers
http:MessageHeader Message Header A header in an HTTP message. http:GeneralHeader, http:RequestHeader, http:ResponseHeader, http:EntityHeader http:fieldName, http:fieldValue, http:hdrName, http:headerElements
http:Method Method The HTTP method used for a request. -
http:Parameter Parameter A parameter for a part of a header value - http:paramName, http:paramValue
http:Request Request An HTTP request. - http:methodName, http:requestURI, http:mthd, http:resp
http:RequestHeader Request Header A header in an HTTP request message. - http:fieldName, http:fieldValue, http:hdrName, http:headerElements
http:Response Response An HTTP response. - http:statusCodeValue, http:reasonPhrase, http:sc
http:ResponseHeader Response Header A general header in an HTTP response message. - http:fieldName, http:fieldValue, http:hdrName, http:headerElements
http:StatusCode Status Code The status code of an HTTP response. - http:statusCodeNumber

Properties

Properties in the HTTP-in-RDF namespace
Property name Label Comment Domain Range
http:absolutePath Request URI Request URI that is an absolute path. http:Request RDF Literal
http:absoluteURI Request URI Request URI that is an absolute URI http:Request RDF Literal
http:authority Request URI Request URI that is an authority. http:Request RDF Literal
http:body Entity body The entity body of an HTTP message. http:Message cnt:ContentAsBase64
http:connectionAuthority Connection authority The authority of a connection used for the HTTP transfer http:Connection RDF Literal
http:elementName Header element name The name of a header element http:HeaderElement RDF Literal
http:elementValue Header element value The value of a header element. http:HeaderElement RDF Literal
http:fieldName Field name The name of an HTTP header field. http:MessageHeader RDF Literal
http:fieldValue Field value The value of an HTTP header field. http:MessageHeader RDF Literal
http:hdrName Header name The name of an HTTP header. http:MessageHeader http:HeaderName
http:headerElements Header elements The deconstructed parts of an HTTP header value. http:MessageHeader Collection of http:HeaderElement
http:headers Headers The headers in an HTTP message. http:Message Collection of http:MessageHeader
http:httpVersion HTTP Version The HTTP version of an HTTP message. http:Message RDF Literal
http:methodName Method name The HTTP method name used for the HTTP request. http:Request RDF Literal
http:mthd Method The HTTP method used for the HTTP request. http:Request http:Method
http:paramName Parameter name The name of a parameter in a part of a deconstructed HTTP header value. http:Parameter RDF Literal
http:params Parameters The parameters in a part of a deconstructed HTTP header value. http:HeaderElement Collection of http:Parameter
http:paramValue Parameter value The value of a parameter in a part of a deconstructed HTTP header value. http:Parameter RDF Literal
http:reasonPhrase Reason phrase The reason phrase (status text) of an HTTP response. http:Response RDF Literal
http:requests Requests The HTTP requests made via a connection. http:Connection Collection of http:Request
http:requestURI Request URI The request URI of an HTTP request. http:Request RDF Literal
http:resp Response The HTTP response sent in answer to an HTTP request. http:Request http:Response
http:sc Status code The status code of an HTTP response. http:Response http:StatusCode
http:statusCodeNumber Status code number The standardized status code number. http:StatusCode http://www.w3.org/2001/XMLSchema#int
http:statusCodeValue Status code value The status code value of an HTTP response. http:Response RDF Literal

Appendix C: References

[Content-in-RDF]
Representing Content in RDF - Johannes Koch, Carlos A Velasco, Philip Ackermann (editors). W3C Working Draft 27 April 2011.
[EARL]
Evaluation and Report Language (EARL) Overview - W3C
[HTTP Status Codes]
"HTTP Status Code Registry" - IANA.
[OWL]
Web Ontology Language (OWL) Overview - W3C
[Permanent Headers]
Permanent Message Header Field Names - IANA.
[Provisional Headers]
Provisional Message Header Field Names - IANA.
[POWDER-DR]
Protocol for Web Description Resources (POWDER): Description Resources - P. Archer, K. Smith, A. Perego (editors). W3C Proposed Recommendation 04 June 2009.
[RDF]
Resource Description Framework (RDF) Overview - W3C
[RDF-PRIMER]
RDF Primer - Frank Manola, Eric Miller (editors). W3C Recommendation, 10 February 2004.
[RDFS]
RDF Vocabulary Description Language 1.0: RDF Schema - Dan Brickley, R.V. Guha (editors). W3C Recommendation 10 February 2004
[RFC2119]
Request for Comments (RFC): 2119. Key words for use in RFCs to Indicate Requirement Levels - IETF March 1997.
[RFC2616]
Hypertext Transfer Protocol -- HTTP/1.1 - R. Fielding, J. Gettys, J. Mogul, H. Frystyk Nielsen, L. Masinter, P. Leach and T. Berners-Lee. IETF June 1999.
[RFC4229]
HTTP Header Field Registrations - M. Nottingham, J. Mogul. IETF December 2005.
[RFC5789]
PATCH Method for HTTP - L. Dusseault, Linden Lab, J. Snell. IETF March 2010.
[WCAG]
Web Content Accessibility Guidelines (WCAG) Overview - W3C.
[XML]
Extensible Markup Language (XML) 1.0 (Fifth Edition) - Tim Bray, Jean Paoli, C. M. Sperberg-McQueen, Eve Maler, Fran├žois Yergeau (editors). W3C Recommendation 26 November 2008

Appendix D: Document Changes

The following is a list of substantial changes since the 29 October 2009 Working Draft: