Expressing Dublin Core™ metadata using HTML/XHTML meta and link elements

Creator:	Pete Johnston Eduserv Foundation, UK
Creator:	Andy Powell Eduserv Foundation, UK
Date Issued:	2008-08-04
Identifier:	//www.voudr.com/specifications/dublin-core/dc-html/2008-08-04/
Replaces:	//www.voudr.com/specifications/dublin-core/dcq-html/2003-11-30/
Replaces:	//www.voudr.com/specifications/dublin-core/dc-html/2007-11-05/
Is Replaced By:	Not applicable
Latest Version:	//www.voudr.com/specifications/dublin-core/dc-html/
Status of Document:	This is a DCMIRecommendation
Description of Document:	This document describes how a Dublin Core™ metadata description set can be encoded in HTML/XHTML and elements. It is an HTML meta data profile, as defined by the HTML specification.

Table of contents

1. Introduction
2. The DCMI Abstract Model and DC-HTML
3. Features of the DC-HTML Syntax
4. The DC-HTML Meta Data Profile
5. Addendum
6. Appendix A. DC-TEXT Representation of Examples
7. 附录b . RDF / XML表示的例子
8. References
9. Acknowledgements

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1. Introduction

This document specifies a set of conventions by which a DC metadatadescription setcan be can be represented within an X/HTML Web page using X/HTML elements and attributes. Formally, it defines ameta data profilefor HTML and XHTML; the profile is identified by the URI//www.voudr.com/specifications/dublin-core/dc-html/2008-08-04/and is referred to in this document as the "DC-HTML" meta data profile.

The "Description Set Model" of the DCMI Abstract Model [ABSTRACT-MODEL] describes the constructs that make up a DC metadatadescription set. In order to represent a DC metadata description set in an X/HTML document those constructs have to be represented as components in that X/HTML document, i.e. as X/HTML elements and attributes and as element content and attribute values.

This profile makes use only of the X/HTMLandelements and their attributes.

1.1 DC-HTML and GRDDL

The W3C RecommendationGleaning Resource Descriptions from Dialects of Languages[GRDDL] describes a set of conventions for associating an XML document with an algorithm for the extraction of a set of RDF triples from that document. One of the mechanisms defined by GRDDL is the association of a Profile Transformation with an XHTML meta data profile.

The GRDDL Profile Transformation for the DC-HTML meta data profile ishttp://purl.org/dc/transform/dc-html-20080804-grddl/dc-html2rdfxml.xsl.

1.2 GRDDL, XML and Entity References [added 17 May 2010]

The GRDDL specification notes that a GRDDL XML processor might not process DTDs and schemas referenced by a document, and recommends:

Document authors, particularly XHTML document authors, who wish their documents to be unambiguous when used with GRDDL should avoid dependencies on an externalDTD subset; specifically:

• Explicitly include the XHTML namespace declaration in an XHTML document, or an appropriate namespace in an XML document.
• Avoid use of entity references, except those listed insection 4.6 of the XML specification.
• And, more generally, follow the rules listed forthe standalone documentvalidity constraint.

So, XHTML documents using the DC-HTML profile shouldnotinclude entity references other than the five predefined by the XML specification itself (&, <, >, ', "). Numeric character references (like © or © for the copyright sign)aresupported.

2. The DCMI Abstract Model and DC-HTML

According to the "Description Set Model" of the DCMI Abstract Model [ABSTRACT-MODEL], a DCdescription sethas the following structure:

• adescription setis made up of one or moredescriptions

• adescriptionis made up of

  • zero or onedescribed resource URIand

  • one or morestatements

• astatementis made up of

  • exactly oneproperty URIand

  • exactly onevalue surrogate

• avalue surrogateis either aliteral value surrogateor anon-literal value surrogate

  • aliteral value surrogateis made up of

    • exactly onevalue string

  • anon-literal value surrogateis made up of

    • zero or onevalue URIs

    • zero or onevocabulary encoding scheme URIs

    • zero or morevalue strings

• avalue stringis either aplain value stringor atyped value string

  • aplain value stringmay be associated with avalue string language

  • atyped value stringis associated with asyntax encoding scheme URI

• anon-literal valuemay be described by anotherdescription

The conventions described in this document implement the following subset of the DCAM "description set model".

• adescription setis made up of onedescription

• adescriptionis made up of

  • onedescribed resource URIand

  • one or morestatements

• astatementis made up of

  • exactly oneproperty URIand

  • exactly onevalue surrogate

• avalue surrogateis either aliteral value surrogateor anon-literal value surrogate

  • aliteral value surrogateis made up of

    • exactly onevalue string

  • anon-literal value surrogateis made up of

    • exactly onevalue URI

    • zero or oneplain value strings

• avalue stringis either aplain value stringor atyped value string

  • aplain value stringmay be associated with avalue string language

  • atyped value stringis associated with asyntax encoding scheme URI

The differences between the full set of components of thedescription setand the subset supported by the DC-HTML meta data profile are summarised in the following table:

Component	DCAM Description Model	DC-HTML
description set	One	One
description	One-to-many descriptions	One description
described resource URI	One per description; any URI	One per description;document URI/Base URI
statement	One-to-many statements per description	One-to-many statements per description
property URI	One per statement; any URI	One per statement; any URI
literal value surrogate	One per statement	One per statement;partial support
literal value surrogate / value string	One per literal value surrogate	One per literal value surrogate;partial support
literal value surrogate / value string language	Zero-to-one per value string	Zero-to-one per value string
文字值代理/ SES URI	Zero-to-one per value string	Zero-to-one per value string;XML Literal datatype not supported
non-literal value surrogate	One per statement	One per statement;partial support
non-literal value surrogate / value string	Zero-to-many per non-literal value surrogate	Zero-to-one per non-literal value surrogate;partial support
non-literal value surrogate / value string language	Zero-to-one per value string	Zero-to-one per value string
non-literal value surrogate / SES URI	Zero-to-one per value string	Not supported
non-literal value surrogate / value URI	Zero-to-one per non-literal value surrogate	One per non-literal value surrogate
non-literal value surrogate / VES URI	Zero to one per non-literal value surrogate	Not supported

i.e. the conventions here support adescription setcontaining a singledescription, and a maximum of onevalue stringpervalue surrogate. In anon-literal value surrogate,avalue URImust be providedand avalue stringmust be aplain value string.The provision of avocabulary encoding scheme URIis not supported.

3. Features of the DC-HTML Meta Data Profile

3.1 URIs in DC-HTML

The DCAM uses Uniform Resource Identifiers (URIs) [RFC3986] to refer both to the resources described and to metadata terms (properties,classes,vocabulary encoding schemesandsyntax encoding schemes).

In the DC-HTML profile, those URIs are encoded as X/HTML attribute values. Later sections of this document describe the use of those different X/HTML attributes in detail. The purpose of this section is to make some general points about the representation of these URIs in DC-HTML.

3.1.1 URI references

In the DC-HTML profile,value URIsare encoded as URI references, used as X/HTML attribute values. A URI reference is either a URI or a relative reference [RFC3986].

The URI may be represented in full. The following example shows avalue URIas the value of thehrefattribute:

Example 1: URI as attribute value (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
  href="http://example.org/topics/archives"> 
   

Example 2: URI as attribute value (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
  href="http://example.org/topics/archives"/> 
   

For all of the attributes in DC-HTML which have URIs as values, the value may also be a relative reference. The relative reference is resolved relative to a base URI, obtained either from the value of thehrefattribute of thebaseelement or from the URI of the document itself. In the following example, the value of thehrefattribute is a relative reference. It is resolved relative to the base URI provided by thehrefattribute of thebaseelement to obtain a target URI ofhttp://example.org/docs/doc123:

Example 3: Relative reference as attribute value (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
   href="//www.voudr.com/www/specifications/dublin-core/dc-html/doc123"> 
   

Example 4: Relative reference as attribute value (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
   href="//www.voudr.com/www/specifications/dublin-core/dc-html/doc123"/> 
   

3.1.2 URIs,

DC-HTML Prefixed Names and Namespace Declarations

In DC-HTML,property URIsandsyntax encoding scheme URIsare represented as DC-HTML Prefixed Names.

A DC-HTML Prefixed Name is an abbreviation for a URI used in the DC-HTML format. A DC-HTML Prefixed Name consists of a "prefix" followed by a period (".") and a "local name".

The "prefix" in a DC-HTML Prefixed Name is associated with a "namespace URI" using a namespace declaration, made using a Namespace Declaration Element (see the section on Namespace Declarationsbelow). The URI represented by the DC-HTML Prefixed Name is determined by concatenating the "namespace URI" with which the prefix is associated and the "local name".

For a software application that is "encoding" adescription setby generating a DC-HTML instance, a DC-HTML Prefixed Name to represent a URI is determined by

• dividing the URI into a pair consisting of a local name (the trailing characters of the URI) and a namespace URI (the preceding part of the URI), and

• providing a Namespace Declaration element for this namespace URI (using a prefix in the namespace declaration and in the DC-HTML Prefixed Name).

Note that this means for a single URI there is more than one possible DC-HTML Prefixed Name representation. For example, the URIhttp://purl.org/dc/terms/titlemight be represented using any of the following (namespace URI, local name) pairs:

• {http://purl.org/dc/terms/}, title

• {http://purl.org/dc/terms/t}, itle

• {http://purl.org/dc/terms/ti}, tle

• {http://purl.org/dc/terms/tit}, le

• {http://purl.org/dc/terms/titl}, e

Communities typically decide on a convention for the DC-HTML Prefixed Name to be used for a URI, particularly for the URIs of terms (properties,classes,vocabulary encoding schemesandsyntax encoding schemes), but in theory any of these four forms could be deployed without changing the interpretation of the instance. For all DCMI terms, the convention used by the DCMI community is to split the term URI into an expanded name at the right-most '/' (forward slash) character (as in the first example above). Also, the characters used for the prefix in a DC-HTML Prefixed Name are not significant, but communities often adopt a convention on the common use of a prefix to facilitate human readability.

The following examples shows a namespace declaration and the use of a DC-HTML Prefixed Name for the value of thenameattribute of themetaelement:

Example 5: DC-HTML Prefixed Name as attribute value (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
< link rel = "模式。直流" href = " http://purl.org/dc/elements/1.1/" >name="DC.title"content="Services to Government" > 
   

Example 6: DC-HTML Prefixed Name as attribute value (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
< link rel = "模式。直流" href = " http://purl.org/dc/elements/1.1/" />name="DC.title"content="Services to Government" /> 
   

In a DC-HTML Prefixed Name, the prefix is the part of the name preceding the first period character; the remainder of the string following the period is treated as the "local name" and appended to the "namespace URI". If a DC-HTML Prefixed Name contains more than one period character, the prefix is the part preceding the first period, and the local name is the remainder of the name following the first period, and any subsequent period characters simply form part of the local name.

In the following example the DC-HTML Prefixed Name "XX.date.removed" corresponds to the URIhttp://example.org/terms/date.removed

Example 7: DC-HTML Prefixed Name as attribute value (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
< link rel = "模式。XX" href="http://example.org/terms/" >name="XX.date.removed"content="2007-05-05" > 
   

Example 8: DC-HTML Prefixed Name as attribute value (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
< link rel = "模式。XX" href="http://example.org/terms/" />name="XX.date.removed"content="2007-05-05" /> 
   

如果DC-HTML前缀的名称中使用的前缀not been associated with a URI in a namespace declaration, no URI can be generated for that DC-HTML Prefixed Name. If the prefix has been associated with multiple URIs (though multiple namespace declarations) then the prefix is associated with the namespace URI specified in the latest declaration for that prefix in the DC-HTML instance.

In the following examples the prefix "XX" is used in a a DC-HTML Prefixed Name, but there is no namespace declaration for that prefix so no URI is generated for that value of thenameattribute of themetaelement:

Example 9: DC-HTML Prefixed Name as attribute value, missing namespace declaration (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
   name="XX.approved"content="2007-01-05" > 
   

Example 10: DC-HTML Prefixed Name as attribute value, missing namespace declaration (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
   name="XX.approved"content="2007-01-05" /> 
   

In the following examples the prefix "XX" is used in a a DC-HTML Prefixed Name, and there are two namespace declaration for that prefix. The second namespace declaration is used to generate the URIhttp://your.example.org/terms/approvedfrom the value of thenameattribute of themetaelement:

Example 11: DC-HTML Prefixed Name as attribute value, multiple namespace declarations (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
 < link rel = "模式。XX" href="http://my.example.org/terms/" >< link rel = "模式。XX" href="http://your.example.org/terms/" > name="XX.approved"content="2007-01-05" > 
   

Example 12: DC-HTML Prefixed Name as attribute value, multiple namespace declarations (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
 < link rel = "模式。XX" href="http://my.example.org/terms/" />< link rel = "模式。XX" href="http://your.example.org/terms/" /> name="XX.approved"content="2007-01-05" /> 
   

4. The DC-HTML Meta Data Profile

4.1 The

Profile Attribute Value

Where these conventions are used to represent a DC metadata_description set_ in an X/HTML document, the value of theprofileattribute of the X/HTMLheadelement must include the URI of this X/HTML metadata profile//www.voudr.com/specifications/dublin-core/dc-html/2008-08-04/

4.2 DC-HTML

Namespace Declarations

A DC-HTML namespace declaration associates a URI with a prefix, so that when that prefix is used in a DC-HTML Prefixed Name, that URI is used as a "namespace URI". A namespace declaration is made using the X/HTMLlinkelement and a specific convention for the value of therelattribute. In the DC-HTML profile, an X/HTMLlinkelement of which therelattribute has a value beginning with the charactersschema.represents a namespace declaration.

The DC-HTML namespace declaration must include:

• a prefix, represented by part of the value of therelattribute of the X/HTMLlinkelement following the charactersschema.

• a namespace URI, represented by the value of thehrefattribute of the X/HTMLlinkelement

In the following example, declarations are provided for two prefixes, each of which is used subsequently in a DC-HTML Prefixed Name.

Example 13: The Namespace Declaration (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
< link rel = "模式。直流" href = " http://purl.org/dc/elements/1.1/" >< link rel = "模式。MARCREL" href="http://www.loc.gov/loc.terms/relators/" >  
   

Example 14: The Namespace Declaration (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
< link rel = "模式。直流" href = " http://purl.org/dc/elements/1.1/" />< link rel = "模式。MARCREL" href="http://www.loc.gov/loc.terms/relators/" />  
   

4.3 Encoding

a Description Set

Adescription setis made up of one_description_.

In the DC-HTML profile, thedescription setis not explicitly represented, but thestatementsrepresented constitute a singledescriptionwithin adescription set.

4.4 Encoding

a Description

Adescriptionis a set of one or more_statements_ about a resource.

In the DC-HTML profile, thedescriptionis not explicitly represented, but thestatementsrepresented constitute a singledescription.

4.4.1 The

Described Resource URI

Adescriptionhas an associateddescribed resource URI.

In the DC-HTML profile, the _described resource URI_is the URI of the X/HTML document

4.5 Encoding

a Statement

Adescriptionis made up of one or more_statements_.

In the DC-HTML profile, eachstatementis represented as either an X/HTMLmetaelement or an X/HTMLlinkelement. The choice of X/HTML element depends on whether thestatementcontains aliteral value surrogateor anon-literal value surrogate.

The examples below show adescriptionconsisting of two_statements_.

Example 15: Statements as meta and link elements (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
  
   

Example 16: Statements as meta and link elements (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
  
   

4.5.1 Encoding a Statement containing a Literal Value Surrogate

In the DC-HTML profile, eachstatementcontaining a_literal values surrogate_ is represented as an X/HTMLmetaelement.

4.5.1.1 The

Property URI

Astatementmust contain exactly oneproperty URI.

In the DC-HTML profile, aproperty URIin a_statement_ containing a _literal values surrogate_is represented as a DC-HTML Prefixed Name which is the value of thenameattribute of an X/HTMLmetaelement.

The examples below shows adescriptionconsisting of a singlestatementwhere theproperty URIishttp://purl.org/dc/terms/title.

Example 17: The Property URI as the value of the name Attribute (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
  name="DC.title"content="Services to Government" > 
   

Example 18: The Property URI as the value of the name Attribute (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
  name="DC.title"content="Services to Government" /> 
   

4.5.1.2 Encoding a Literal Value Surrogate

Aliteral value surrogateis made up of exactly one_value string_.

In the DC-HTML profile, avalue stringwithin a_literal values surrogate_ is represented by the combination of the values of several attributes of an X/HTMLmetaelement.

Avalue stringis either a _plain value string_or atyped value string.

Aplain value stringmay be associated with avalue string language.

In the DC-HTML profile, the string itself is represented as the value of thecontentattribute of an X/HTMLmetaelement, and avalue string languageis represented by the value of thelang(HTML) orxml:lang(XHTML) attribute of themetaelement.

The examples below shows adescriptionconsisting of a singlestatementwith a _literal value surrogate_made up of aplain value stringwith novalue string language.

Example 19: Literal Value Surrogate Plain Value String as value of content Attribute (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
  content="Services to Government"> 
   

Example 20: Literal Value Surrogate Plain Value String as value of content Attribute (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
  content="Services to Government"/> 
   

The examples below shows adescriptionconsisting of a singlestatementwith a _literal value surrogate_made up of aplain value stringwhich includes avalue string language.

Example 21: Literal Value Surrogate Plain Value String with Value String Language (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
  lang="en"content="Services to Government" > 
   

Example 22: Literal Value Surrogate Plain Value String with Value String Language (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
  xml:lang="en"content="Services to Government" /> 
   

Atyped value stringis associated with asyntax encoding scheme URI.

In the DC-HTML profile, the string itself is represented as the value of thecontentattribute of an X/HTMLmetaelement, and asyntax encoding scheme URIis represented as a DC-HTML Prefixed Name which is the value of theschemeattribute of the X/HTMLmetaelement.

The examples below show adescriptionconsisting of two_statements_ withliteral value surrogates. In the secondstatementtheliteral value surrogatecontains atyped value stringwith the_syntax encoding scheme URI_http://www.w3.org/2001/XMLSchema#date:

Example 23: Literal Value Surrogate with Typed Value String (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
     scheme="XSD.date"content="2007-07-22" > 
   

Example 24: Literal Value Surrogate with Typed Value String (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
     scheme="XSD.date"content="2007-07-22" /> 
   

4.5.2 Encoding a Statement containing a Non-Literal Value Surrogate

In the DC-HTML profile, eachstatementcontaining a_non-literal values surrogate_ is represented as an X/HTMLlinkelement.

4.5.2.1. The

Property URI

Astatementmust contain exactly oneproperty URI.

In the DC-HTML profile, aproperty URIin a_statement_ containing anon-literal values surrogateis represented as a DC-HTML Prefixed Name which is the value of therelattribute of an X/HTMLlinkelement.

The examples below shows adescriptionconsisting of a singlestatementwhere theproperty URIishttp://purl.org/dc/terms/subject.

Example 25: The Property URI as the value of the rel attribute (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
  rel="DCTERMS.subject"href="http://example.org/topics/archives" title="Archives" > 
   

Example 26: The Property URI as the value of the rel attribute (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
  rel="DCTERMS.subject"href="http://example.org/topics/archives" title="Archives" /> 
   

The X/HTML rel attribute supports a list of linktypes, so where adescriptioncontains multiplestatements_referring to differentpropertiesbut the same_value, they may be represented using a singlelinkelement.

The examples below shows adescriptionconsisting of twostatementswhere theproperty URIsarehttp://purl.org/dc/terms/creatorandhttp://purl.org/dc/terms/publisher.

Example 27: Multiple Property URIs as the value of the rel attribute (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
  rel="DCTERMS.creator DCTERMS.publisher"href="http://example.org/agents/DCMI" title="Dublin Core™ Metadata Initiative" > 
   

Example 28: Multiple Property URIs as the value of the rel attribute (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
  rel="DCTERMS.creator DCTERMS.publisher"href="http://example.org/agents/DCMI" title="Dublin Core™ Metadata Initiative" /> 
   

The samedescriptioncould be represented using repeatedlinkelements:

Example 29: The Property URI as the value of the rel attribute (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
 
   

Example 30: The Property URI as the value of the rel attribute (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
 
   

4.5.2.2. Encoding a Non-Literal Value Surrogate

的子集DCAM suppor描述模型ted by the DC-HTML profile, anon-literal value surrogateis made up of exactly onevalue URIand zero or oneplain value strings.

In the DC-HTML profile, thevalue URIis represented as the value of thehrefattribute of the X/HTMLlinkelement

The examples below shows adescriptionconsisting of a singlestatementwith anon-literal value surrogatemade up of avalue URI.

Example 31: Non-Literal Value Surrogate with Value URI as value of href attribute (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
  href="http://example.org/topics/archives"> 
   

Example 32: Non-Literal Value Surrogate with Value URI as value of href attribute (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
  href="http://example.org/topics/archives"/> 
   

Aplain value stringmay be associated with avalue string language.

In the DC-HTML profile, the string itself is represented as the value of thetitleattribute of the X/HTMLlinkelement, and avalue string languageis represented by the value of thelang(HTML) orxml:lang(XHTML) attribute of thelinkelement.

The examples below shows adescriptionconsisting of a singlestatementwith anon-literal value surrogatemade up of avalue URIand aplain value stringwith novalue string language.

Example 33: Non-Literal Value Surrogate with Plain Value String as value of title attribute (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
   
   

Example 34: Non-Literal Value Surrogate Plain Value String as value of title attribute (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
   
   

The examples below shows adescriptionconsisting of a singlestatementwith anon-literal value surrogatemade up of avalue URIand aplain value stringwhich includes avalue string language.

Example 35: Non-Literal Value Surrogate with Plain Value String with Value String Language (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
   
   

Example 36: Non-Literal Value Surrogate Plain Value String with Value String Language (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
   
   

Addendum

1. Additional Notes on Namespace Declarations

1.1 Case in Prefix Matching

The case of the characters in the stringschema.is not significant. If the value of therelattribute of the X/HTMLlinkelement begins with the stringsSCHEMA.orsChEmA., then the element is interpreted as a namespace declaration.

Note also that the matching of the prefix in a DC-HTML Prefixed Name to the prefix in the namespace declaration isnotcase-sensitive, e.g. a prefix of "dc" in the value of thenameattribute of themetaelement will match a prefix of "DC" in the value of therelattribute of thelinkelement.

In the following example the namespace declaration associates the prefix "DC" with the namespace URIhttp://purl.org/dc/elements/1.1/, and the DC-HTML Prefixed Name "dc.title" corresponds to the URIhttp://purl.org/dc/elements/1.1/title

Example Add 01: The Namespace Declaration: Case in Prefix Matching (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
 
   

Example Add 02: The Namespace Declaration: Case in Prefix Matching (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
 
   

Note, however, that caseissignificant in the interpretation of the URIs generated from DC-HTML prefixed names by a DCAM/RDF application: e.g. the two URIshttp://example.org//terms/titleandhttp://example.org//terms/Titleare not considered equal.

1.2 Prefix Conventions

It is important to note that the use of prefixes such as "DC" or "DCTERMS" is simply a community convention. There is no requirement that these prefixes are associated with the namespace URIshttp://purl.org/dc/elements/1.1/andhttp://purl.org/dc/terms/

In the following example the namespace declaration associates the prefix "DC" with the namespace URIhttp://example.org/terms/, and the DC-HTML Prefixed Name "DC.date" corresponds to the URIhttp://example.org/terms/date

Example Add 03: The Namespace Declaration: Prefix Conventions (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
< link rel = "模式。DC" href="http://example.org/terms/" >name="DC.date"content="2007-05-05" > 
   

Example Add 04: The Namespace Declaration: Prefix Conventions (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
< link rel = "模式。DC" href="http://example.org/terms/" />name="DC.date"content="2007-05-05" /> 
   

Similarly, the namespace URIshttp://purl.org/dc/elements/1.1/andhttp://purl.org/dc/terms/may be associated with any prefixes.

In the following example the namespace declaration associates the prefix "XX" with the namespace URIhttp://purl.org/dc/elements/1.1/, and the DC-HTML Prefixed Name "XX.date" corresponds to the URIhttp://purl.org/dc/elements/1.1/date

Example Add 05: The Namespace Declaration: Prefix Conventions (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
< link rel = "模式。XX" href="http://purl.org/dc/elements/1.1/" >name="XX.date"content="2007-05-05" > 
   

Example Add 06: The Namespace Declaration: Prefix Conventions (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
< link rel = "模式。XX" href="http://purl.org/dc/elements/1.1/" />name="XX.date"content="2007-05-05" /> 
   

1.3 Omitted Declarations

如果DC-HTML前缀的名称中使用的前缀not been associated with a URI in a namespace declaration, no URI can be generated for that DC-HTML Prefixed Name.

In the following examples the prefixes "XX" and "DCTERMS" are used in DC-HTML Prefixed Names, but there are no namespace declarations for those prefixes so no URI is generated for those values of thenameattribute of themetaelement. Note that this applies to the "DCTERMS" prefix, as well as to the "XX" prefix: the "DC" and "DCTERMS" prefixes are not subject to any special treatment; there are no "built-in" namespace declarations.

Example Add 07: The Namespace Declaration: Omitted Declarations (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
   name="XX.approved"content="2007-01-05" > name="DCTERMS.issued"content="2007-01-04" > 
   

Example Add 08: The Namespace Declaration: Omitted Declarations (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
   name="XX.approved"content="2007-01-05" /> name="DCTERMS.issued"content="2007-01-04" /> 
   

1.4 Multiple Declarations

If the prefix has been associated with multiple URIs (though multiple namespace declarations) then the prefix is associated with the namespace URI specified in the latest declaration for that prefix in the DC-HTML instance.

In the following examples the prefix "XX" is used in a DC-HTML Prefixed Name, and there are two namespace declaration for that prefix. The second namespace declaration is used to generate the URIhttp://your.example.org/terms/approvedfrom the value of thenameattribute of themetaelement:

Example Add 09: The Namespace Declaration: Multiple Declarations (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
 < link rel = "模式。XX" href="http://my.example.org/terms/" >< link rel = "模式。XX" href="http://your.example.org/terms/" > name="XX.approved"content="2007-01-05" > 
   

Example Add 10: The Namespace Declaration: Multiple Declarations (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
 < link rel = "模式。XX" href="http://my.example.org/terms/" />< link rel = "模式。XX" href="http://your.example.org/terms/" /> name="XX.approved"content="2007-01-05" /> 
   

1.5 Prefixed Names Preceding Declarations

Themetaorlinkelements containing the DC-HTML prefixed names innameandrelattribute values may occur before thelinkelements representing namespace declarations for the prefixes used. As above, in the case of multiple declarations for a single prefix, the latest declaration for the prefix is used.

In the following examples, the second namespace declaration is used to generate the URIhttp://your.example.org/terms/approvedfrom the value of thenameattribute of themetaelement:

Example Add 11: The Namespace Declaration: Prefixed Names Preceding Declarations (HTML)

<！DOCTYPE html公共”——/ / W3C / / DTD html 4.01 / / EN”"http://www.w3.org/TR/html4/strict.dtd">   
  name="XX.approved"content="2007-01-05" > < link rel = "模式。XX" href="http://my.example.org/terms/" >< link rel = "模式。XX" href="http://your.example.org/terms/" >
   

Example Add 12: The Namespace Declaration: Prefixed Names Preceding Declarations (XHTML)

<？xml version="1.0" encoding="utf-8" ?>    
  name="XX.approved"content="2007-01-05" /> < link rel = "模式。XX" href="http://my.example.org/terms/" />< link rel = "模式。XX" href="http://your.example.org/terms/" />
   

Appendix A.

DC-TEXT Representation of Example Description Sets

This appendix provides representations of all the examples provided in the main body of the document using the DC-Text syntax [DC-TEXT].

A.1 Examples

1 & 2

The X/HTML instances in Examples 1 & 2 represent the following description set:

@prefix dcterms:  . DescriptionSet ( Description ( Statement ( PropertyURI ( dcterms:subject ) ValueURI (  ) ) ) )

A.2 Example

3 & 4

The X/HTML instances in Examples 3 & 4 represent the following description set:

@prefix dcterms:  . DescriptionSet ( Description ( ResourceURI (  ) Statement ( PropertyURI ( dcterms:isReferencedBy ) ValueURI (  ) ) ) )

A.3 Example

5 & 6

The X/HTML instances in Examples 5 & 6 represent the following description set:

@ prefix dc: < http://purl.org/dc/elements/1.1/ >。DescriptionSet ( Description ( Statement ( PropertyURI ( dc:title ) LiteralValueString ( "Services to Government" ) ) ) )

A.4 Example

7 & 8

The X/HTML instances in Examples 11 & 12 represent the following description set:

@prefix xx:  . DescriptionSet ( Description ( Statement ( PropertyURI ( xx:date.removed ) LiteralValueString ( "2007-05-05" ) ) ) )

A.5 Example

9 & 10

The X/HTML instances in Examples 9 & 10 represent the following description set:

@ prefix dc: < http://purl.org/dc/elements/1.1/ >。DescriptionSet ( Description ( Statement ( PropertyURI ( dc:title ) LiteralValueString ( "Services to Government" ) ) ) )

A.6 Example

11 & 12

The X/HTML instances in Examples 11 & 12 represent the following description set:

@ prefix dc: < http://purl.org/dc/elements/1.1/ >。@prefix your:  . DescriptionSet ( Description ( Statement ( PropertyURI ( dc:title ) LiteralValueString ( "Services to Government" ) ) Statement ( PropertyURI ( your:approved ) LiteralValueString ( "2007-01-05" ) ) ) )

A.7 Example

13 & 14

X / HTML实例在13和14代表例子the following description set:

@ prefix dc: < http://purl.org/dc/elements/1.1/ >。@prefix marcrel:  . DescriptionSet ( Description ( Statement ( PropertyURI ( dc:title ) LiteralValueString ( "Services to Government" ) ) Statement ( PropertyURI ( marcrel:EDT ) ValueURI (  ) ) ) )

A.8 Examples

15 & 16

The X/HTML instances in Examples 15 & 16 represent the following description set:

@ prefix dc: < http://purl.org/dc/elements/1.1/ >。@prefix dcterms:  . DescriptionSet ( Description ( Statement ( PropertyURI ( dc:title ) LiteralValueString ( "Services to Government" ) ) Statement ( PropertyURI ( dcterms:subject ) ValueURI (  ) ValueString ( "Archives" ) ) ) )

A.9 Examples

17 & 18

The X/HTML instances in Examples 17 & 18 represent the following description set:

@ prefix dc: < http://purl.org/dc/elements/1.1/ >。DescriptionSet ( Description ( Statement ( PropertyURI ( dc:title ) LiteralValueString ( "Services to Government" ) ) ) )

A.10 Examples

19 & 20

The X/HTML instances in Examples 19 & 20 represent the following description set:

@ prefix dc: < http://purl.org/dc/elements/1.1/ >。DescriptionSet ( Description ( Statement ( PropertyURI ( dc:title ) LiteralValueString ( "Services to Government" ) ) ) )

A.11 Examples

21 & 22

The X/HTML instances in Examples 21 & 22 represent the following description set:

@ prefix dc: < http://purl.org/dc/elements/1.1/ >。DescriptionSet ( Description ( Statement ( PropertyURI ( dc:title ) LiteralValueString ( "Services to Government" Language ( en ) ) ) ) )

A.12 Examples

23 & 24

The X/HTML instances in Examples 23 & 24 represent the following description set:

@ prefix dc: < http://purl.org/dc/elements/1.1/ >。@prefix dcterms:  . DescriptionSet ( Description ( Statement ( PropertyURI ( dc:title ) LiteralValueString ( "Services to Government" Language ( en ) ) ) Statement ( PropertyURI ( dcterms:modified ) LiteralValueString ( "2007-07-22" SyntaxEncodingSchemeURI (  ) ) ) ) )

A.13

Examples 25 & 26

The X/HTML instances in Examples 21 & 22 represent the following description set:

@prefix dcterms:  . DescriptionSet ( Description ( Statement ( PropertyURI ( dcterms:subject ) ValueURI (  ) ValueString ( "Archives" ) ) ) )

A.14

Examples 27 & 28

The X/HTML instances in Examples 27 & 28 represent the following description set:

@prefix dcterms:  . DescriptionSet ( Description ( Statement ( PropertyURI ( dcterms:creator ) ValueURI (  ) ValueString ( "Dublin Core™ Metadata Initiative" ) ) Statement ( PropertyURI ( dcterms:publisher ) ValueURI (  ) ValueString ( "Dublin Core™ Metadata Initiative" ) ) ) )

A.15

Examples 29 & 30

The X/HTML instances in Examples 29 & 30 represent the following description set:

@prefix dcterms:  . DescriptionSet ( Description ( Statement ( PropertyURI ( dcterms:publisher ) ValueURI (  ) ValueString ( "Dublin Core™ Metadata Initiative" ) ) Statement ( PropertyURI ( dcterms:publisher ) ValueURI (  ) ValueString ( "Dublin Core™ Metadata Initiative" ) ) ) )

A.16

Examples 31 & 32

The X/HTML instances in Examples 31 & 32 represent the following description set:

@prefix dcterms:  . DescriptionSet ( Description ( Statement ( PropertyURI ( dcterms:subject ) ValueURI (  ) ) ) )

A.17

Examples 33 & 34

The X/HTML instances in Examples 33 & 34 represent the following description set:

@prefix dcterms:  . DescriptionSet ( Description ( Statement ( PropertyURI ( dcterms:subject ) ValueURI (  ) ValueString ( "Archives" ) ) ) )

A.18

Examples 35 & 36

The X/HTML instances in Examples 35 & 36 represent the following description set:

@prefix dcterms:  . DescriptionSet ( Description ( Statement ( PropertyURI ( dcterms:subject ) ValueURI (  ) ValueString ( "Archives" Language ( en ) ) ) ) )

A.19 Examples Add 01 & Add 02

The X/HTML instances in Examples Add 01 & Add 02 represent the following description set:

@ prefix dc: < http://purl.org/dc/elements/1.1/ >。DescriptionSet ( Description ( Statement ( PropertyURI ( dc:title ) LiteralValueString ( "Services to Government" ) ) ) )

A.20 Examples Add 03 & Add 04

The X/HTML instances in Examples Add 03 & Add 04 represent the following description set:

@prefix dc:  . DescriptionSet ( Description ( Statement ( PropertyURI ( dc:date ) LiteralValueString ( "2007-05-05" ) ) ) )

A.21 Examples Add 05 & Add 06

The X/HTML instances in Examples Add 05 & Add 06 represent the following description set:

@prefix xx:  . DescriptionSet ( Description ( Statement ( PropertyURI ( xx:date ) LiteralValueString ( "2007-05-05" ) ) ) )

A.22 Examples Add 07 & Add 08

The X/HTML instances in Examples Add 07 & Add 08 represent the following description set:

@ prefix dc: < http://purl.org/dc/elements/1.1/ >。DescriptionSet ( Description ( Statement ( PropertyURI ( dc:title ) LiteralValueString ( "Services to Government" ) ) ) )

A.23 Examples Add 09 & Add 10

The X/HTML instances in Examples Add 09 & Add 10 represent the following description set:

@ prefix dc: < http://purl.org/dc/elements/1.1/ >。@prefix your:  . DescriptionSet ( Description ( Statement ( PropertyURI ( dc:title ) LiteralValueString ( "Services to Government" ) ) Statement ( PropertyURI ( your:approved ) LiteralValueString ( "2007-01-05" ) ) ) )

A.24 Examples Add 11 & Add 12

The X/HTML instances in Examples Add 11 & Add 12 represent the following description set:

@ prefix dc: < http://purl.org/dc/elements/1.1/ >。@prefix your:  . DescriptionSet ( Description ( Statement ( PropertyURI ( dc:title ) LiteralValueString ( "Services to Government" ) ) Statement ( PropertyURI ( your:approved ) LiteralValueString ( "2007-01-05" ) ) ) )

Appendix B.

RDF/XML Representation of Examples

This appendix provides representations of all the examples provided in the main body of the document using the RDF/XML syntax [RDFXML].

B.1 Examples

1 & 2

The X/HTML instances in Examples 1 & 2 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>     

B.2 Example

3 & 4

The X/HTML instances in Examples 3 & 4 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>     

B.3 Example

5 & 6

The X/HTML instances in Examples 5 & 6 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>   Services to Government  

B.4 Example

7 & 8

The X/HTML instances in Examples 7 & 8 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>  xmlns:xx="http://example.org/terms/" >  2007-05-05  

B.5 Example

9 & 10

The HTML/XHTML instances in Examples 9 & 10 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>   Services to Government  

B.6 Example

11 & 12

The X/HTML instances in Examples 11 & 12 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>  xmlns:your="http://your.example.org/terms/" >  Services to Government 2007-01-05  

B.7 Example

13 & 14

X / HTML实例在13和14代表例子the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>  xmlns:marcrel="http://www.loc.gov/loc.terms/relators/" >  Services to Government   

B.8 Examples

15 & 16

The X/HTML instances in Examples 15 & 16 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>   Services to Government   

B.9 Examples

17 & 18

The X/HTML instances in Examples 17 & 18 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>   Services to Government  

B.10 Examples

19 & 20

The X/HTML instances in Examples 19 & 20 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>   Services to Government  

B.11 Examples

21 & 22

The X/HTML instances in Examples 21 & 22 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>   Services to Government  

B.12 Examples

23 & 24

The X/HTML instances in Examples 23 & 24 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>   Services to Government 2007-07-22  

B.13

Examples 25 & 26

The X/HTML instances in Examples 21 & 22 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>     

B.14

Examples 27 & 28

The X/HTML instances in Examples 27 & 28 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>      

B.15

Examples 29 & 30

The X/HTML instances in Examples 29 & 30 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>      

B.16

Examples 31 & 32

The X/HTML instances in Examples 31 & 32 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>     

B.17

Examples 33 & 34

The X/HTML instances in Examples 33 & 34 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>     

B.18

Examples 35 & 36

The X/HTML instances in Examples 35 & 36 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>     

B.19 Examples Add 01 & Add 02

The HTML/XHTML instances in Examples Add 01 & Add 02 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>   Services to Government  

B.20 Examples Add 03 & Add 04

The HTML/XHTML instances in Examples Add 03 & Add 04 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>   2007-05-05  

B.21 Examples Add 05 & Add 06

The HTML/XHTML instances in Examples Add 05 & Add 06 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>   2007-05-05  

B.22 Examples Add 07 & Add 08

The HTML/XHTML instances in Examples Add 07 & Add 08 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>   Services to Government  

B.23 Examples Add 09 & Add 10

The HTML/XHTML instances in Examples Add 09 & Add 10 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>  xmlns:your="http://your.example.org/terms/" >  Services to Government 2007-01-05  

B.20 Examples Add 11 & Add 12

The HTML/XHTML instances in Examples Add 11 & Add 12 represent the following RDF graph:

<？xml version="1.0" encoding="UTF-8" ?>  xmlns:your="http://your.example.org/terms/" >  Services to Government 2007-01-05  

References

[ABSTRACT-MODEL]
DCMI Abstract ModelDCMI Recommendation. 2007-06-04
//www.voudr.com/specifications/dublin-core/abstract-model/2007-06-04/

[DC-TEXT]
Expressing Dublin Core™ metadata using the DC-Text formatDCMI Recommended Resource. 2007-12-03
//www.voudr.com/specifications/dublin-core/dc-text/2007-12-03/

[GRDDL]
Gleaning Resource Descriptions from Dialects of Languages (GRDDL)W3C Recommendation 11 September 2007
http://www.w3.org/TR/2007/REC-grddl-20070911/

[RDFXML]
RDF/XML Syntax Specification (Revised)W3C Recommendation 10 February 2004
http://www.w3.org/TR/2004/REC-rdf-syntax-grammar-20040210/

[RFC3986]
Berners-Lee, T., R. Fielding, L. Masinter. RFC 3986: Uniform Resource Identifier (URI): Generic Syntax. Internet Engineering Task Force (IETF). January 2005.
<http://www.ietf.org/rfc/rfc3986.txt>

Acknowledgements

This document draws on the existing recommendations for encoding Dublin Core™ metadata in HTML, including documents by John Kunze, Simon Cox, Eric Miller and Andy Powell, and on comments made by Julian Reschke.

Errata

2010-05-17: Addded section 1.2 on standalone validity and entity references.

2010-05-17: Changed entity reference from to .

2010-02-15: Corrected profile URI values in twelve examples in Addendum.

2010-02-15:纠正两个日期之前的勘误表变化.

2009-09-21: Changed value of profile attribute of this document to refer to bothhttp://www.w3.org/2003/g/data-viewand//www.voudr.com/specifications/dublin-core/dc-html/2008-08-04/profiles

2009-09-21: In section 3.1.2, changed "the latest declaration in the DC-HTML instance" to "the latest declaration for that prefix in the DC-HTML instance"

2009-09-21:添加附录emph名称空间声明asise that case is not significant in matching prefix to namespace declaration; the prefixes "DC" and "DCTERMS" may be associated with any "namespace URI", and the "namespace URIs"http://purl.org/dc/elements/1.1/andhttp://purl.org/dc/terms/may be associated with any prefix; namespace declarations are required for all prefixes, including "DC" and "DCTERMS"; and that the use of a prefix in a may precede a namespace declaration.

2009-09-21: Added new DC-Text and RDF/XML examples to Appendices A and B, corresponding to the new examples in the Addendum.