--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/spec/FCGS/json-ld-syntax/20130222/diff-20130202.html Fri Feb 22 12:58:40 2013 +0100
@@ -0,0 +1,19394 @@
+<!DOCTYPE html>
+<html lang="en" dir="ltr" prefix="bibo: http://purl.org/ontology/bibo/" typeof="bibo:Document">
+<head>
+<title>JSON-LD 1.0</title>
+<meta http-equiv="content-type" content="text/html; charset=UTF-8">
+
+
+
+<style type="text/css">
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+<style>/*****************************************************************
+ * ReSpec 3 CSS
+ * Robin Berjon - http://berjon.com/
+ *****************************************************************/
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+a.bibref {
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+
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+ text-decoration: none;
+}
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+a .secno, a .figno {
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+/* --- DL --- */
+.section dd > p:first-child {
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+}
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+.section dd {
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+}
+
+.section dl.attrs dd, .section dl.eldef dd {
+ margin-bottom: 0;
+}
+</style><style>/* --- EXAMPLES --- */
+div.example-title {
+ min-width: 7.5em;
+ color: #b9ab2d;
+}
+div.example-title span {
+ text-transform: uppercase;
+}
+aside.example, div.example, div.illegal-example {
+ padding: 0.5em;
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+ clear: both;
+}
+div.illegal-example { color: red }
+div.illegal-example p { color: black }
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+aside.example div.example {
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+ border-color: #999;
+ background: #fff;
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+aside.example div.example div.example-title {
+ color: #999;
+}
+</style><style>/* --- ISSUES/NOTES --- */
+div.issue-title, div.note-title {
+ padding-right: 1em;
+ min-width: 7.5em;
+ color: #b9ab2d;
+}
+div.issue-title { color: #e05252; }
+div.note-title { color: #52e052; }
+div.issue-title span, div.note-title span {
+ text-transform: uppercase;
+}
+div.note, div.issue {
+ margin-top: 1em;
+ margin-bottom: 1em;
+}
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+ padding: .5em;
+ border-left-width: .5em;
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+}
+div.issue, div.note {
+ padding: 0.5em;
+ margin: 1em 0;
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+span.note, span.issue { padding: .1em .5em .15em; }
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+ background: #fbe9e9;
+}
+.note {
+ border-color: #52e052;
+ background: #e9fbe9;
+}
+
+
+</style><link href="http://www.w3.org/community/src/css/spec/cg-final.css" rel="stylesheet"><!--[if lt IE 9]><script src='http://www.w3.org/2008/site/js/html5shiv.js'></script><![endif]--><!--[if lt IE 9]><script src='http://www.w3.org/2008/site/js/html5shiv.js'></script><![endif]--><style type='text/css'>
+.diff-old-a {
+ font-size: smaller;
+ color: red;
+}
+
+.diff-new { background-color: yellow; }
+.diff-chg { background-color: lime; }
+.diff-new:before,
+.diff-new:after
+ { content: "\2191" }
+.diff-chg:before, .diff-chg:after
+ { content: "\2195" }
+.diff-old { text-decoration: line-through; background-color: #FBB; }
+.diff-old:before,
+.diff-old:after
+ { content: "\2193" }
+:focus { border: thin red solid}
+</style>
+</head>
+
+
+<body>
+<div class="head">
+<p>
+<a href="http://www.w3.org/">
+<img src="http://www.w3.org/Icons/w3c_home" alt="W3C" height="48" width="72">
+</a>
+</p>
+<h1 class="title" id="title">
+JSON-LD
+1.0
+</h1>
+<h2 id="subtitle">
+A
+JSON-based
+Serialization
+for
+Linked
+Data
+</h2>
+<h2 id="final-community-group-specification-22-february-2013">
+Final
+Community
+Group
+Specification
+<del class="diff-old">02
+</del>
+<ins class="diff-chg">22
+</ins>
+February
+2013
+</h2>
+<dl>
+<dt>
+Latest
+editor's
+draft:
+</dt>
+<dd>
+<a href="http://dvcs.w3.org/hg/json-ld/raw-file/default/spec/latest/json-ld-syntax/index.html">
+http://dvcs.w3.org/hg/json-ld/raw-file/default/spec/latest/json-ld-syntax/index.html
+</a>
+</dd>
+<dt>
+Editors:
+</dt>
+<dd rel="bibo:editor" inlist="">
+<span typeof="foaf:Person">
+<a rel="foaf:homepage" property="foaf:name" content="Manu Sporny" href="http://manu.sporny.org/">
+Manu
+Sporny
+</a>,
+<a rel="foaf:workplaceHomepage" href="http://digitalbazaar.com/">
+Digital
+Bazaar
+</a>
+</span>
+</dd>
+<dd rel="bibo:editor" inlist="">
+<span typeof="foaf:Person">
+<a rel="foaf:homepage" property="foaf:name" content="Gregg Kellogg" href="http://greggkellogg.net/">
+Gregg
+Kellogg
+</a>,
+<a rel="foaf:workplaceHomepage" href="http://kellogg-assoc.com/">
+Kellogg
+Associates
+</a>
+</span>
+</dd>
+<dd rel="bibo:editor" inlist="">
+<span typeof="foaf:Person">
+<a rel="foaf:homepage" property="foaf:name" content="Markus Lanthaler" href="http://www.markus-lanthaler.com/">
+Markus
+Lanthaler
+</a>,
+<a rel="foaf:workplaceHomepage" href="http://www.tugraz.at/">
+Graz
+University
+of
+Technology
+</a>
+</span>
+</dd>
+<dt>
+Authors:
+</dt>
+<dd rel="dcterms:contributor">
+<span typeof="foaf:Person">
+<a rel="foaf:homepage" property="foaf:name" content="Manu Sporny" href="http://digitalbazaar.com/">
+Manu
+Sporny
+</a>,
+<a rel="foaf:workplaceHomepage" href="http://digitalbazaar.com/">
+Digital
+Bazaar
+</a>
+</span>
+</dd>
+<dd rel="dcterms:contributor">
+<span typeof="foaf:Person">
+<a rel="foaf:homepage" property="foaf:name" content="Dave Longley" href="http://digitalbazaar.com/">
+Dave
+Longley
+</a>,
+<a rel="foaf:workplaceHomepage" href="http://digitalbazaar.com/">
+Digital
+Bazaar
+</a>
+</span>
+</dd>
+<dd rel="dcterms:contributor">
+<span typeof="foaf:Person">
+<a rel="foaf:homepage" property="foaf:name" content="Gregg Kellogg" href="http://greggkellogg.net/">
+Gregg
+Kellogg
+</a>,
+<a rel="foaf:workplaceHomepage" href="http://kellogg-assoc.com/">
+Kellogg
+Associates
+</a>
+</span>
+</dd>
+<dd rel="dcterms:contributor">
+<span typeof="foaf:Person">
+<a rel="foaf:homepage" property="foaf:name" content="Markus Lanthaler" href="http://www.markus-lanthaler.com/">
+Markus
+Lanthaler
+</a>,
+<a rel="foaf:workplaceHomepage" href="http://www.tugraz.at/">
+Graz
+University
+of
+Technology
+</a>
+</span>
+</dd>
+<dd rel="dcterms:contributor">
+<span typeof="foaf:Person">
+<a rel="foaf:homepage" property="foaf:name" content="Niklas Lindström" href="http://neverspace.net/">
+Niklas
+Lindström
+</a>
+</span>
+</dd>
+</dl>
+<p>
+This
+document
+is
+also
+available
+in
+this
+non-normative
+format:
+<a class="alt-format" href="diff-20130202.html">
+diff
+to
+previous
+version
+</a>
+</p>
+<p class="copyright">
+<a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">
+Copyright
+</a>
+©
+2010-2013
+the
+Contributors
+to
+the
+JSON-LD
+1.0
+Specification,
+published
+by
+the
+<a href="http://www.w3.org/2011/rdf-wg/">
+RDF
+Working
+Group
+</a>
+under
+the
+<a href="https://www.w3.org/community/about/agreements/fsa/">
+W3C
+Community
+Final
+Specification
+Agreement
+(FSA)
+</a>.
+A
+human-readable
+<a href="http://www.w3.org/community/about/agreements/fsa-deed/">
+summary
+</a>
+is
+available.
+</p>
+<hr>
+</div>
+<section rel="bibo:chapter" resource="#abstract" typeof="bibo:Chapter" datatype="" property="dcterms:abstract" class="introductory" id="abstract">
+<h2>
+Abstract
+</h2>
+<p>
+JSON
+has
+proven
+to
+be
+a
+highly
+useful
+object
+serialization
+and
+messaging
+format.
+In
+an
+attempt
+to
+harmonize
+the
+representation
+of
+<a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">
+Linked
+Data
+</a>
+in
+JSON,
+this
+specification
+outlines
+a
+common
+JSON
+representation
+format
+for
+expressing
+directed
+graphs;
+mixing
+both
+Linked
+Data
+and
+non-Linked
+Data
+in
+a
+single
+document.
+</p>
+</section>
+<section rel="bibo:chapter" resource="#sotd" typeof="bibo:Chapter" id="sotd" class="introductory">
+<h2>
+Status
+of
+This
+Document
+</h2>
+<p>
+This
+specification
+was
+published
+by
+the
+<a href="http://www.w3.org/2011/rdf-wg/">
+RDF
+Working
+Group
+</a>.
+It
+is
+not
+a
+W3C
+Standard
+nor
+is
+it
+on
+the
+W3C
+Standards
+Track.
+Please
+note
+that
+under
+the
+<a href="https://www.w3.org/community/about/agreements/final/">
+W3C
+Community
+Final
+Specification
+Agreement
+(FSA)
+</a>
+other
+conditions
+apply.
+Learn
+more
+about
+<a href="http://www.w3.org/community/">
+W3C
+Community
+and
+Business
+Groups
+</a>.
+</p>
+<p>
+This
+document
+has
+been
+under
+development
+for
+over
+25
+months
+in
+the
+JSON
+for
+Linking
+Data
+Community
+Group.
+The
+document
+has
+recently
+been
+transferred
+to
+the
+RDF
+Working
+Group
+for
+review,
+improvement,
+and
+publication.
+The
+specification
+has
+undergone
+significant
+development,
+review,
+and
+changes
+during
+the
+course
+of
+the
+last
+25
+months.
+</p>
+<p>
+There
+are
+several
+independent
+<a href="http://json-ld.org/#impl">
+interoperable
+implementations
+</a>
+of
+this
+specification.
+There
+is
+a
+<a href="https://github.com/json-ld/json-ld.org/tree/master/test-suite">
+fairly
+complete
+test
+suite
+</a>
+and
+a
+<a href="http://json-ld.org/playground/">
+live
+JSON-LD
+editor
+</a>
+that
+is
+capable
+of
+demonstrating
+the
+features
+described
+in
+this
+document.
+While
+development
+on
+implementations,
+the
+test
+suite
+and
+the
+live
+editor
+will
+continue,
+they
+are
+believed
+to
+be
+mature
+enough
+to
+be
+integrated
+into
+a
+non-production
+system
+at
+this
+point
+in
+time
+with
+the
+expectation
+that
+they
+could
+be
+used
+in
+a
+production
+system
+within
+the
+next
+year.
+</p>
+<p>
+There
+are
+a
+number
+of
+ways
+that
+one
+may
+participate
+in
+the
+development
+of
+this
+specification:
+</p>
+<ul>
+<li>
+If
+you
+want
+to
+make
+sure
+that
+your
+feedback
+is
+formally
+addressed
+by
+the
+RDF
+Working
+Group,
+you
+should
+send
+it
+to
+public-rdf-comments:
+<a href="http://lists.w3.org/Archives/Public/public-rdf-comments/">
+public-rdf-comments@w3.org
+</a>
+</li>
+<li>
+Ad-hoc
+technical
+discussion
+primarily
+occurs
+on
+the
+public
+community
+mailing
+list:
+<a href="http://lists.w3.org/Archives/Public/public-linked-json/">
+public-linked-json@w3.org
+</a>
+</li>
+<li>
+<a href="http://json-ld.org/minutes/">
+Public
+JSON-LD
+Community
+Group
+teleconferences
+</a>
+are
+held
+on
+Tuesdays
+at
+1500UTC
+every
+week.
+</li>
+<li>
+RDF
+Working
+Group
+teleconferences
+are
+held
+on
+Wednesdays
+at
+1500UTC
+every
+week.
+Participation
+is
+limited
+to
+RDF
+Working
+Group
+members.
+</li>
+<li>
+Specification
+bugs
+and
+issues
+should
+be
+reported
+in
+the
+<a href="https://github.com/json-ld/json-ld.org/issues">
+issue
+tracker
+</a>
+if
+you
+do
+not
+want
+to
+send
+an
+e-mail
+to
+the
+public-rdf-comments
+mailing
+list.
+</li>
+<li>
+<a href="https://github.com/json-ld/json-ld.org/tree/master/spec">
+Source
+code
+</a>
+for
+the
+specification
+can
+be
+found
+on
+Github.
+</li>
+<li>
+The
+<a href="http://webchat.freenode.net/?channels=json-ld">
+#json-ld
+</a>
+IRC
+channel
+is
+available
+for
+real-time
+discussion
+on
+irc.freenode.net.
+</li>
+</ul>
+</section>
+<section id="toc">
+<h2 class="introductory">
+Table
+of
+Contents
+</h2>
+<ul class="toc">
+<li class="tocline">
+<a class="tocxref" href="#introduction">
+<span class="secno">
+1.
+</span>
+Introduction
+</a>
+<ul class="toc">
+<li class="tocline">
+<a class="tocxref" href="#how-to-read-this-document">
+<span class="secno">
+1.1
+</span>
+How
+to
+Read
+this
+Document
+</a>
+</li>
+</ul>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#design-goals-and-rationale">
+<span class="secno">
+2.
+</span>
+Design
+Goals
+and
+Rationale
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#terminology">
+<span class="secno">
+3.
+</span>
+Terminology
+</a>
+<ul class="toc">
+<li class="tocline">
+<a class="tocxref" href="#general-terminology">
+<span class="secno">
+3.1
+</span>
+General
+Terminology
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#syntax-tokens-and-keywords">
+<span class="secno">
+3.2
+</span>
+Syntax
+Tokens
+and
+Keywords
+</a>
+</li>
+</ul>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#conformance">
+<span class="secno">
+4.
+</span>
+Conformance
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#basic-concepts">
+<span class="secno">
+5.
+</span>
+Basic
+Concepts
+</a>
+<ul class="toc">
+<li class="tocline">
+<a class="tocxref" href="#the-context">
+<span class="secno">
+5.1
+</span>
+The
+Context
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#iris">
+<span class="secno">
+5.2
+</span>
+IRIs
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#node-identifiers">
+<span class="secno">
+5.3
+</span>
+Node
+Identifiers
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#specifying-the-type">
+<span class="secno">
+5.4
+</span>
+Specifying
+the
+Type
+</a>
+</li>
+</ul>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#advanced-concepts">
+<span class="secno">
+6.
+</span>
+Advanced
+Concepts
+</a>
+<ul class="toc">
+<li class="tocline">
+<a class="tocxref" href="#compact-iris">
+<span class="secno">
+6.1
+</span>
+Compact
+IRIs
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#typed-values">
+<span class="secno">
+6.2
+</span>
+Typed
+Values
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#type-coercion">
+<span class="secno">
+6.3
+</span>
+Type
+Coercion
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#advanced-context-usage">
+<span class="secno">
+6.4
+</span>
+Advanced
+Context
+Usage
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#interpreting-json-as-json-ld">
+<span class="secno">
+<del class="diff-old">6.4.1
+</del>
+<ins class="diff-chg">6.5
+</ins>
+</span>
+Interpreting
+JSON
+as
+JSON-LD
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#string-internationalization">
+<span class="secno">
+<del class="diff-old">6.5
+</del>
+<ins class="diff-chg">6.6
+</ins>
+</span>
+String
+Internationalization
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#overriding-vocab">
+<span class="secno">
+<del class="diff-old">6.6
+</del>
+<ins class="diff-chg">6.7
+</ins>
+</span>
+Overriding
+@vocab
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#property-generators">
+<span class="secno">
+<del class="diff-old">6.7
+</del>
+<ins class="diff-chg">6.8
+</ins>
+</span>
+Property
+Generators
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#iri-expansion-within-a-context">
+<span class="secno">
+<del class="diff-old">6.8
+</del>
+<ins class="diff-chg">6.9
+</ins>
+</span>
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+Expansion
+Within
+a
+Context
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#sets-and-lists">
+<span class="secno">
+<del class="diff-old">6.9
+</del>
+<ins class="diff-chg">6.10
+</ins>
+</span>
+Sets
+and
+Lists
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#embedding">
+<span class="secno">
+<del class="diff-old">6.10
+</del>
+<ins class="diff-chg">6.11
+</ins>
+</span>
+Embedding
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#named-graphs">
+<span class="secno">
+<del class="diff-old">6.11
+</del>
+<ins class="diff-chg">6.12
+</ins>
+</span>
+Named
+Graphs
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#identifying-blank-nodes">
+<span class="secno">
+<del class="diff-old">6.12
+</del>
+<ins class="diff-chg">6.13
+</ins>
+</span>
+Identifying
+Blank
+Nodes
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#aliasing-keywords">
+<span class="secno">
+<del class="diff-old">6.13
+</del>
+<ins class="diff-chg">6.14
+</ins>
+</span>
+Aliasing
+Keywords
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#expanded-document-form">
+<span class="secno">
+<del class="diff-old">6.14
+</del>
+<ins class="diff-chg">6.15
+</ins>
+</span>
+Expanded
+Document
+Form
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#compact-document-form">
+<span class="secno">
+<del class="diff-old">6.15
+</del>
+<ins class="diff-chg">6.16
+</ins>
+</span>
+Compact
+Document
+Form
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#data-indexing">
+<span class="secno">
+<del class="diff-old">6.16
+</del>
+<ins class="diff-chg">6.17
+</ins>
+</span>
+Data
+Indexing
+</a>
+</li>
+</ul>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#data-model">
+<span class="secno">
+A.
+</span>
+Data
+Model
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#json-ld-grammar">
+<span class="secno">
+B.
+</span>
+JSON-LD
+Grammar
+</a>
+<ul class="toc">
+<li class="tocline">
+<a class="tocxref" href="#grammar-node-object">
+<span class="secno">
+B.1
+</span>
+Node
+Object
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#grammar-term-reference">
+<span class="secno">
+B.2
+</span>
+Term
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#grammar-language-map">
+<span class="secno">
+B.3
+</span>
+Language
+Map
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#grammar-index-map">
+<span class="secno">
+B.4
+</span>
+Index
+Map
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#grammar-expanded-values">
+<span class="secno">
+B.5
+</span>
+Expanded
+Values
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#grammar-set-list">
+<span class="secno">
+B.6
+</span>
+List
+and
+Set
+Values
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#grammar-context">
+<span class="secno">
+B.7
+</span>
+Context
+Definition
+</a>
+</li>
+</ul>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#relationship-to-rdf">
+<span class="secno">
+C.
+</span>
+Relationship
+to
+RDF
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#relationship-to-other-linked-data-formats">
+<span class="secno">
+D.
+</span>
+Relationship
+to
+Other
+Linked
+Data
+Formats
+</a>
+<ul class="toc">
+<li class="tocline">
+<a class="tocxref" href="#turtle">
+<span class="secno">
+D.1
+</span>
+Turtle
+</a>
+<ul class="toc">
+<li class="tocline">
+<a class="tocxref" href="#prefix-definitions">
+<span class="secno">
+D.1.1
+</span>
+Prefix
+definitions
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#embedding-1">
+<span class="secno">
+D.1.2
+</span>
+Embedding
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#lists">
+<span class="secno">
+D.1.3
+</span>
+Lists
+</a>
+</li>
+</ul>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#rdfa">
+<span class="secno">
+D.2
+</span>
+RDFa
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#microformats">
+<span class="secno">
+D.3
+</span>
+Microformats
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#microdata">
+<span class="secno">
+D.4
+</span>
+Microdata
+</a>
+</li>
+</ul>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#iana-considerations">
+<span class="secno">
+E.
+</span>
+IANA
+Considerations
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#acknowledgements">
+<span class="secno">
+F.
+</span>
+Acknowledgements
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#references">
+<span class="secno">
+G.
+</span>
+References
+</a>
+<ul class="toc">
+<li class="tocline">
+<a class="tocxref" href="#normative-references">
+<span class="secno">
+G.1
+</span>
+Normative
+references
+</a>
+</li>
+<li class="tocline">
+<a class="tocxref" href="#informative-references">
+<span class="secno">
+G.2
+</span>
+Informative
+references
+</a>
+</li>
+</ul>
+</li>
+</ul>
+</section>
+<section id="introduction" class="informative">
+<h2>
+<span class="secno">
+1.
+</span>
+Introduction
+</h2>
+<p>
+<em>
+This
+section
+is
+non-normative.
+</em>
+</p>
+<p>
+<dfn id="dfn-linked-data" title="linked-data">
+Linked
+Data
+</dfn>
+is
+a
+technique
+for
+creating
+a
+network
+of
+inter-connected
+data
+across
+different
+documents
+and
+Web
+sites.
+In
+general,
+Linked
+Data
+has
+four
+properties:
+1) it
+uses
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>
+to
+name
+things;
+2) it
+uses
+HTTP
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>
+for
+those
+names;
+3) the
+name
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>,
+when
+dereferenced,
+provide
+more
+information
+about
+the
+name;
+and
+4) the
+data
+expresses
+links
+to
+data
+on
+other
+Web
+sites.
+These
+properties
+allow
+data
+published
+on
+the
+Web
+to
+work
+much
+like
+Web
+pages
+do
+today.
+One
+can
+start
+at
+one
+piece
+of
+Linked
+Data,
+and
+follow
+the
+links
+to
+other
+pieces
+of
+data
+that
+are
+hosted
+on
+different
+sites
+across
+the
+Web.
+</p>
+<p>
+JSON-LD
+is
+designed
+as
+a
+lightweight
+syntax
+to
+express
+<a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">
+Linked
+Data
+</a>
+in
+JSON
+[
+<cite>
+<a href="#bib-RFC4627" class="bibref">
+RFC4627
+</a>
+</cite>
+].
+It
+is
+primarily
+intended
+to
+be
+a
+way
+to
+use
+Linked
+Data
+in
+Web-based
+programming
+environments.
+It
+is
+also
+useful
+when
+building
+interoperable
+Web
+services
+and
+when
+storing
+Linked
+Data
+in
+JSON-based
+storage
+engines.
+Since
+JSON-LD
+is
+100%
+compatible
+with
+JSON
+the
+large
+number
+of
+JSON
+parsers
+and
+libraries
+available
+today
+can
+be
+reused.
+Additionally
+to
+all
+the
+features
+JSON
+provides,
+JSON-LD
+introduces:
+</p>
+<ul>
+<li>
+a
+universal
+identifier
+mechanism
+for
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+objects
+</a>
+via
+the
+use
+of
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>,
+</li>
+<li>
+a
+way
+to
+disambiguate
+the
+keys
+used
+between
+multiple
+JSON
+documents
+by
+mapping
+them
+to
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>
+via
+a
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>,
+</li>
+<li>
+a
+mechanism
+in
+which
+a
+value
+in
+a
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+may
+refer
+to
+a
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+on
+a
+different
+site
+on
+the
+Web,
+</li>
+<li>
+the
+ability
+to
+express
+the
+language
+associated
+with
+a
+<a href="#dfn-string" title="string" class="tref internalDFN">
+string
+</a>
+</li>
+<li>
+a
+way
+to
+associate
+datatypes
+with
+values
+such
+as
+dates,
+times,
+weights,
+and
+distances,
+</li>
+<li>
+and
+a
+facility
+to
+express
+one
+or
+more
+directed
+graphs,
+such
+as
+a
+social
+network,
+in
+a
+single
+document.
+</li>
+</ul>
+<p>
+Developers
+that
+require
+any
+of
+the
+facilities
+listed
+above
+or
+need
+to
+serialize
+an
+RDF
+graph
+or
+dataset
+[
+<cite>
+<a href="#bib-RDF-CONCEPTS" class="bibref">
+RDF-CONCEPTS
+</a>
+</cite>
+]
+in
+a
+JSON-based
+syntax
+will
+find
+JSON-LD
+of
+interest.
+The
+syntax
+is
+designed
+to
+not
+disturb
+already
+deployed
+systems
+running
+on
+JSON,
+but
+provide
+a
+smooth
+upgrade
+path
+from
+JSON
+to
+JSON-LD.
+</p>
+<section id="how-to-read-this-document">
+<h3>
+<span class="secno">
+1.1
+</span>
+How
+to
+Read
+this
+Document
+</h3>
+<p>
+<em>
+This
+section
+is
+non-normative.
+</em>
+</p>
+<p>
+This
+document
+is
+a
+detailed
+specification
+for
+a
+serialization
+of
+Linked
+Data
+in
+JSON.
+The
+document
+is
+primarily
+intended
+for
+the
+following
+audiences:
+</p>
+<ul>
+<li>
+Software
+developers
+that
+want
+to
+encode
+Linked
+Data
+in
+a
+variety
+of
+programming
+languages
+that
+can
+use
+JSON.
+</li>
+<li>
+Software
+developers
+that
+want
+to
+understand
+the
+design
+decisions
+and
+language
+syntax
+for
+JSON-LD.
+</li>
+<li>
+Software
+developers
+that
+want
+to
+implement
+processors
+and
+APIs
+for
+JSON-LD.
+</li>
+</ul>
+<p>
+This
+specification
+does
+not
+describe
+the
+programming
+interfaces
+for
+the
+JSON-LD
+Syntax.
+The
+specification
+that
+describes
+the
+programming
+interfaces
+for
+JSON-LD
+documents
+is
+the
+JSON-LD
+Application
+Programming
+Interface
+[
+<cite>
+<a href="#bib-JSON-LD-API" class="bibref">
+JSON-LD-API
+</a>
+</cite>
+].
+</p>
+<p>
+To
+understand
+the
+basics
+in
+this
+specification
+you
+must
+first
+be
+familiar
+with
+JSON,
+which
+is
+detailed
+in
+[
+<cite>
+<a href="#bib-RFC4627" class="bibref">
+RFC4627
+</a>
+</cite>
+].
+</p>
+</section>
+</section>
+<section id="design-goals-and-rationale" class="informative">
+<h2>
+<span class="secno">
+2.
+</span>
+Design
+Goals
+and
+Rationale
+</h2>
+<p>
+<em>
+This
+section
+is
+non-normative.
+</em>
+</p>
+<p>
+A
+number
+of
+design
+goals
+were
+established
+before
+the
+creation
+of
+this
+markup
+language:
+</p>
+<dl>
+<dt>
+Simplicity
+</dt>
+<dd>
+No
+extra
+processors
+or
+software
+libraries
+should
+be
+necessary
+to
+use
+JSON-LD
+in
+its
+most
+basic
+form.
+The
+language
+will
+provide
+developers
+with
+a
+very
+easy
+learning
+curve.
+Developers
+only
+need
+to
+know
+JSON
+and
+two
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keywords
+</a>
+(
+<code>
+@context
+</code>
+and
+<code>
+@id
+</code>
+)
+to
+use
+the
+basic
+functionality
+in
+JSON-LD.
+</dd>
+<dt>
+Compatibility
+</dt>
+<dd>
+The
+JSON-LD
+markup
+must
+be
+100%
+compatible
+with
+JSON.
+This
+ensures
+that
+all
+of
+the
+standard
+JSON
+libraries
+work
+seamlessly
+with
+JSON-LD
+documents.
+</dd>
+<dt>
+Expressiveness
+</dt>
+<dd>
+The
+syntax
+must
+be
+able
+to
+express
+directed
+graphs,
+which
+have
+been
+proven
+to
+be
+able
+to
+express
+almost
+every
+real
+world
+data
+model.
+</dd>
+<dt>
+Terseness
+</dt>
+<dd>
+The
+JSON-LD
+syntax
+must
+be
+very
+terse
+and
+human
+readable,
+requiring
+as
+little
+effort
+as
+possible
+from
+the
+developer.
+</dd>
+<dt>
+Zero
+Edits,
+most
+of
+the
+time
+</dt>
+<dd>
+JSON-LD
+must
+make
+the
+transition
+to
+JSON-LD
+as
+simple
+as
+possible.
+In
+many
+cases,
+zero
+edits
+to
+the
+JSON
+document
+and
+the
+addition
+of
+one
+line
+to
+the
+HTTP
+response
+should
+suffice
+(see
+<a href="#referencing-contexts-from-json-documents">
+</a>
+).
+This
+allows
+organizations
+that
+have
+already
+deployed
+large
+JSON-based
+infrastructure
+to
+use
+JSON-LD's
+features
+in
+a
+way
+that
+is
+not
+disruptive
+to
+their
+day-to-day
+operations
+and
+is
+transparent
+to
+their
+current
+customers.
+However,
+there
+are
+times
+where
+mapping
+JSON
+to
+a
+graph
+representation
+is
+more
+complex
+than
+a
+simple
+one-line
+change.
+In
+these
+instances,
+rather
+than
+extending
+JSON-LD
+to
+support
+an
+esoteric
+use
+case,
+we
+chose
+not
+to
+support
+the
+use
+case.
+While
+Zero
+Edits
+is
+a
+design
+goal,
+it
+is
+not
+always
+possible
+without
+adding
+great
+complexity
+to
+the
+language.
+We
+should
+focus
+on
+simplicity
+when
+possible.
+</dd>
+</dl>
+</section>
+<section id="terminology" class="normative">
+<h2>
+<span class="secno">
+3.
+</span>
+Terminology
+</h2>
+<section id="general-terminology">
+<h3>
+<span class="secno">
+3.1
+</span>
+General
+Terminology
+</h3>
+<p>
+This
+document
+uses
+the
+following
+terms
+as
+defined
+in
+JSON
+[
+<cite>
+<a href="#bib-RFC4627" class="bibref">
+RFC4627
+</a>
+</cite>
+].
+Refer
+to
+the
+<em>
+JSON
+Grammar
+</em>
+section
+in
+[
+<cite>
+<a href="#bib-RFC4627" class="bibref">
+RFC4627
+</a>
+</cite>
+]
+for
+formal
+definitions.
+</p>
+<dl>
+<dt>
+<dfn id="dfn-json-object" title="json-object">
+JSON
+object
+</dfn>
+</dt>
+<dd>
+An
+object
+structure
+is
+represented
+as
+a
+pair
+of
+curly
+brackets
+surrounding
+zero
+or
+more
+key-value
+pairs.
+A
+key
+is
+a
+<a href="#dfn-string" title="string" class="tref internalDFN">
+string
+</a>.
+A
+single
+colon
+comes
+after
+each
+key,
+separating
+the
+key
+from
+the
+value.
+A
+single
+comma
+separates
+a
+value
+from
+a
+following
+key.
+</dd>
+<dt>
+<dfn id="dfn-array" title="array">
+array
+</dfn>
+</dt>
+<dd>
+An
+array
+structure
+is
+represented
+as
+square
+brackets
+surrounding
+zero
+or
+more
+values.
+Values
+are
+separated
+by
+commas.
+In
+JSON,
+an
+array
+is
+an
+<em>
+ordered
+</em>
+sequence
+of
+zero
+or
+more
+values.
+While
+JSON-LD
+uses
+the
+same
+array
+representation
+as
+JSON,
+the
+collection
+is
+<em>
+unordered
+</em>
+by
+default.
+While
+order
+is
+preserved
+in
+regular
+JSON
+arrays,
+it
+is
+not
+in
+regular
+JSON-LD
+arrays
+unless
+specific
+markup
+is
+provided
+(see
+<a class="sec-ref" href="#sets-and-lists">
+<span class="secno">
+<del class="diff-old">6.9
+</del>
+<ins class="diff-chg">6.10
+</ins>
+</span>
+<span class="sec-title">
+Sets
+and
+Lists
+</span>
+</a>
+).
+</dd>
+<dt>
+<dfn id="dfn-string" title="string">
+string
+</dfn>
+</dt>
+<dd>
+A
+string
+is
+a
+sequence
+of
+zero
+or
+more
+Unicode
+characters,
+wrapped
+in
+double
+quotes,
+using
+backslash
+escapes
+(if
+necessary).
+A
+character
+is
+represented
+as
+a
+single
+character
+string.
+</dd>
+<dt>
+<dfn id="dfn-number" title="number">
+number
+</dfn>
+</dt>
+<dd>
+A
+number
+is
+similar
+to
+that
+used
+in
+most
+programming
+languages,
+except
+that
+the
+octal
+and
+hexadecimal
+formats
+are
+not
+used
+and
+that
+leading
+zeros
+are
+not
+allowed.
+</dd>
+<dt>
+<dfn id="dfn-true" title="true">
+true
+</dfn>
+and
+<dfn id="dfn-false" title="false">
+false
+</dfn>
+</dt>
+<dd>
+Values
+that
+are
+used
+to
+express
+one
+of
+two
+possible
+boolean
+states.
+</dd>
+<dt>
+<dfn id="dfn-null" title="null">
+null
+</dfn>
+</dt>
+<dd>
+The
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>
+value,
+which
+is
+typically
+used
+to
+clear
+or
+forget
+data.
+For
+example,
+A
+key-value
+pair
+in
+the
+<code>
+@context
+</code>
+where
+the
+value
+is
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>
+explicitly
+decouples
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+'s
+association
+with
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>.
+A
+key-value
+pair
+in
+the
+body
+of
+a
+JSON-LD
+document
+whose
+value
+is
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>
+has
+the
+same
+meaning
+as
+if
+the
+key-value
+pair
+was
+not
+defined.
+If
+<code>
+@value
+</code>,
+<code>
+@list
+</code>,
+or
+<code>
+@set
+</code>
+is
+set
+to
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>
+in
+expanded
+form,
+then
+the
+entire
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+is
+ignored.
+</dd>
+</dl>
+</section>
+<section id="syntax-tokens-and-keywords">
+<h3>
+<span class="secno">
+3.2
+</span>
+Syntax
+Tokens
+and
+Keywords
+</h3>
+<p>
+JSON-LD
+specifies
+a
+number
+of
+syntax
+tokens
+and
+<dfn id="dfn-keyword" title="keyword">
+keywords
+</dfn>
+that
+are
+a
+core
+part
+of
+the
+language:
+</p>
+<dl>
+<dt>
+<code>
+@context
+</code>
+</dt>
+<dd>
+Used
+to
+define
+the
+short-hand
+names
+that
+are
+used
+throughout
+a
+JSON-LD
+document.
+These
+short-hand
+names
+are
+called
+<a href="#dfn-term" title="term" class="tref internalDFN">
+terms
+</a>
+and
+help
+developers
+to
+express
+specific
+identifiers
+in
+a
+compact
+manner.
+The
+<code>
+@context
+</code>
+keyword
+is
+described
+in
+detail
+in
+the
+section
+titled
+<a class="sec-ref" href="#the-context">
+<span class="secno">
+5.1
+</span>
+<span class="sec-title">
+The
+Context
+</span>
+</a>.
+</dd>
+<dt>
+<code>
+@id
+</code>
+</dt>
+<dd>
+Used
+to
+uniquely
+identify
+<em>
+things
+</em>
+that
+are
+being
+described
+in
+the
+document.
+This
+keyword
+is
+described
+in
+<a class="sec-ref" href="#node-identifiers">
+<span class="secno">
+5.3
+</span>
+<span class="sec-title">
+Node
+Identifiers
+</span>
+</a>.
+</dd>
+<dt>
+<code>
+@value
+</code>
+</dt>
+<dd>
+Used
+to
+specify
+the
+data
+that
+is
+associated
+with
+a
+particular
+<a href="#dfn-property" title="property" class="tref internalDFN">
+property
+</a>
+in
+the
+graph.
+This
+keyword
+is
+described
+in
+<a class="sec-ref" href="#string-internationalization">
+<span class="secno">
+<del class="diff-old">6.5
+</del>
+<ins class="diff-chg">6.6
+</ins>
+</span>
+<span class="sec-title">
+String
+Internationalization
+</span>
+</a>
+and
+<a class="sec-ref" href="#typed-values">
+<span class="secno">
+6.2
+</span>
+<span class="sec-title">
+Typed
+Values
+</span>
+</a>.
+</dd>
+<dt>
+<code>
+@language
+</code>
+</dt>
+<dd>
+Used
+to
+specify
+the
+native
+language
+for
+a
+particular
+value
+or
+the
+default
+language
+of
+a
+JSON-LD
+document.
+This
+keyword
+is
+described
+in
+the
+section
+titled
+<a class="sec-ref" href="#string-internationalization">
+<span class="secno">
+<del class="diff-old">6.5
+</del>
+<ins class="diff-chg">6.6
+</ins>
+</span>
+<span class="sec-title">
+String
+Internationalization
+</span>
+</a>.
+</dd>
+<dt>
+<code>
+@type
+</code>
+</dt>
+<dd>
+Used
+to
+set
+the
+data
+type
+of
+a
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>
+or
+<a href="#dfn-typed-value" title="typed-value" class="tref internalDFN">
+typed
+value
+</a>.
+This
+keyword
+is
+described
+in
+the
+section
+titled
+<a class="sec-ref" href="#typed-values">
+<span class="secno">
+6.2
+</span>
+<span class="sec-title">
+Typed
+Values
+</span>
+</a>.
+</dd>
+<dt>
+<code>
+@container
+</code>
+</dt>
+<dd>
+Used
+to
+set
+the
+default
+container
+type
+for
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>.
+This
+keyword
+is
+described
+in
+the
+section
+titled
+<a class="sec-ref" href="#sets-and-lists">
+<span class="secno">
+<del class="diff-old">6.9
+</del>
+<ins class="diff-chg">6.10
+</ins>
+</span>
+<span class="sec-title">
+Sets
+and
+Lists
+</span>
+</a>.
+</dd>
+<dt>
+<code>
+@list
+</code>
+</dt>
+<dd>
+Used
+to
+express
+an
+ordered
+set
+of
+data.
+This
+keyword
+is
+described
+in
+the
+section
+titled
+<a class="sec-ref" href="#sets-and-lists">
+<span class="secno">
+<del class="diff-old">6.9
+</del>
+<ins class="diff-chg">6.10
+</ins>
+</span>
+<span class="sec-title">
+Sets
+and
+Lists
+</span>
+</a>.
+</dd>
+<dt>
+<code>
+@set
+</code>
+</dt>
+<dd>
+Used
+to
+express
+an
+unordered
+set
+of
+data
+and
+to
+ensure
+that
+values
+are
+always
+represented
+as
+arrays.
+This
+keyword
+is
+described
+in
+the
+section
+titled
+<a class="sec-ref" href="#sets-and-lists">
+<span class="secno">
+<del class="diff-old">6.9
+</del>
+<ins class="diff-chg">6.10
+</ins>
+</span>
+<span class="sec-title">
+Sets
+and
+Lists
+</span>
+</a>.
+</dd>
+<dt>
+<code>
+@index
+</code>
+</dt>
+<dd>
+Used
+to
+specify
+that
+a
+container
+is
+used
+to
+index
+information
+and
+that
+processing
+should
+continue
+deeper
+into
+a
+JSON
+data
+structure.
+This
+keyword
+is
+described
+in
+the
+section
+titled
+<a class="sec-ref" href="#data-indexing">
+<span class="secno">
+<del class="diff-old">6.16
+</del>
+<ins class="diff-chg">6.17
+</ins>
+</span>
+<span class="sec-title">
+Data
+Indexing
+</span>
+</a>.
+</dd>
+<dt>
+<code>
+@vocab
+</code>
+</dt>
+<dd>
+Used
+to
+expand
+properties
+and
+values
+in
+<code>
+@type
+</code>
+with
+a
+common
+prefix
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>.
+This
+keyword
+is
+described
+in
+section
+<a class="sec-ref" href="#iris">
+<span class="secno">
+5.2
+</span>
+<span class="sec-title">
+IRIs
+</span>
+</a>.
+</dd>
+<dt>
+<code>
+@graph
+</code>
+</dt>
+<dd>
+Used
+to
+explicitly
+label
+a
+<a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">
+JSON-LD
+graph
+</a>.
+This
+keyword
+is
+described
+in
+<a class="sec-ref" href="#named-graphs">
+<span class="secno">
+<del class="diff-old">6.11
+</del>
+<ins class="diff-chg">6.12
+</ins>
+</span>
+<span class="sec-title">
+Named
+Graphs
+</span>
+</a>.
+</dd>
+<dt>
+<code>:
+</code>
+</dt>
+<dd>
+The
+separator
+for
+JSON
+keys
+and
+values
+that
+use
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+IRIs
+</a>.
+</dd>
+</dl>
+<p>
+For
+the
+avoidance
+of
+doubt,
+all
+keys,
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keywords
+</a>,
+and
+values
+in
+JSON-LD
+are
+case-sensitive.
+</p>
+</section>
+</section>
+<section id="conformance" class="normative">
+<h2>
+<span class="secno">
+4.
+</span>
+Conformance
+</h2>
+<p>
+This
+specification
+describes
+the
+conformance
+criteria
+for
+JSON-LD
+documents.
+This
+criteria
+is
+relevant
+to
+authors
+and
+authoring
+tool
+implementers.
+</p>
+<p>
+A
+<a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">
+JSON-LD
+document
+</a>
+complies
+with
+this
+specification
+if
+it
+follows
+the
+normative
+statements
+in
+section
+<a class="sec-ref" href="#json-ld-grammar">
+<span class="secno">
+B.
+</span>
+<span class="sec-title">
+JSON-LD
+Grammar
+</span>
+</a>.
+JSON
+documents
+can
+be
+interpreted
+as
+JSON-LD
+by
+following
+the
+normative
+statements
+in
+section
+<a href="#referencing-contexts-from-json-documents">
+</a>.
+For
+convenience,
+normative
+statements
+for
+documents
+are
+often
+phrased
+as
+statements
+on
+the
+properties
+of
+the
+document.
+</p>
+<p>
+The
+key
+words
+<em title="must" class="rfc2119">
+must
+</em>,
+<em title="must not" class="rfc2119">
+must
+not
+</em>,
+<em title="required" class="rfc2119">
+required
+</em>,
+<em title="shall" class="rfc2119">
+shall
+</em>,
+<em title="shall not" class="rfc2119">
+shall
+not
+</em>,
+<em title="should" class="rfc2119">
+should
+</em>,
+<em title="should not" class="rfc2119">
+should
+not
+</em>,
+<em title="recommended" class="rfc2119">
+recommended
+</em>,
+<em title="not recommended" class="rfc2119">
+not
+recommended
+</em>,
+<em title="may" class="rfc2119">
+may
+</em>,
+and
+<em title="optional" class="rfc2119">
+optional
+</em>
+in
+this
+specification
+have
+the
+meaning
+defined
+in
+[
+<cite>
+<a href="#bib-RFC2119" class="bibref">
+RFC2119
+</a>
+</cite>
+].
+</p>
+</section>
+<section id="basic-concepts" class="normative">
+<h2>
+<span class="secno">
+5.
+</span>
+Basic
+Concepts
+</h2>
+<p>
+JSON
+[
+<cite>
+<a href="#bib-RFC4627" class="bibref">
+RFC4627
+</a>
+</cite>
+]
+is
+a
+lightweight,
+language-independent
+data-interchange
+format.
+It
+is
+easy
+to
+parse
+and
+easy
+to
+generate.
+However,
+it
+is
+difficult
+to
+integrate
+JSON
+from
+different
+sources
+as
+the
+data
+has
+just
+local
+meaning.
+Furthermore,
+JSON
+has
+no
+built-in
+support
+for
+hyperlinks
+-
+a
+fundamental
+building
+block
+on
+the
+Web.
+Let's
+look
+at
+an
+example
+that
+we
+will
+be
+using
+for
+the
+rest
+of
+this
+section:
+</p>
+<del class="diff-old"> {
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/",
+ "image": "http://manu.sporny.org/images/manu.png"
+</del>
+ <div class="example"><div class="example-title"><span>Example 1</span>: Sample JSON document</div><pre class="example">{
+<ins class="diff-chg"> "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/",
+ "image": "http://manu.sporny.org/images/manu.png"
+</ins>
+}
+</pre>
+</div>
+<p>
+It's
+obvious
+for
+humans
+that
+the
+data
+is
+about
+a
+person
+whose
+name
+is
+"Manu
+Sporny"
+and
+that
+the
+<code>
+homepage
+</code>
+property
+contains
+the
+URL
+of
+that
+person's
+homepage.
+A
+machine
+doesn't
+have
+such
+an
+intuitive
+understanding
+and
+sometimes,
+even
+for
+humans,
+it
+is
+difficult
+to
+resolve
+ambiguities
+in
+such
+representations.
+This
+problem
+can
+be
+solved
+by
+using
+unambiguous
+identifiers
+to
+denote
+the
+different
+concepts
+instead
+of
+<a href="#dfn-term" title="term" class="tref internalDFN">
+terms
+</a>
+such
+as
+"name",
+"homepage",
+etc.
+</p>
+<p>
+<a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">
+Linked
+Data
+</a>,
+and
+the
+Web
+in
+general,
+uses
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>
+(Internationalized
+Resource
+Identifiers
+as
+described
+in
+[
+<cite>
+<a href="#bib-RFC3987" class="bibref">
+RFC3987
+</a>
+</cite>
+])
+for
+unambiguous
+identification.
+The
+idea
+is
+to
+assign
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>
+to
+something
+that
+may
+be
+of
+use
+to
+other
+developers
+and
+that
+it
+is
+useful
+to
+give
+them
+an
+unambiguous
+identifier.
+That
+is,
+it
+is
+useful
+for
+<a href="#dfn-term" title="term" class="tref internalDFN">
+terms
+</a>
+to
+expand
+to
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>
+so
+that
+developers
+don't
+accidentally
+step
+on
+each
+other's
+terms.
+Furthermore,
+developers
+and
+machines
+are
+able
+to
+use
+this
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+(by
+using
+a
+web
+browser,
+for
+instance)
+to
+go
+to
+the
+term
+and
+get
+a
+definition
+of
+what
+the
+term
+means.
+</p>
+<p>
+Leveraging
+the
+well-known
+<a href="http://schema.org/">
+schema.org
+vocabulary
+</a>,
+the
+example
+above
+could
+be
+unambiguously
+expressed
+as
+follows:
+</p>
+<del class="diff-old"> {
+ "": "Manu Sporny",
+ ",
+ "
+</del>
+ <div class="example"><div class="example-title"><span>Example 2</span>: Sample JSON-LD document using full IRIs instead of terms</div><pre class="example">{
+<ins class="diff-chg"> "<span class="diff">http://schema.org/name</span>": "Manu Sporny",
+ "<span class="diff">http://schema.org/url</span>": <span class="diff">{ "@id": </span>"http://manu.sporny.org/" <span class="diff">}</span>,
+ "<span class="diff">http://schema.org/image</span>": <span class="diff">{ "@id": </span>"http://manu.sporny.org/images/manu.png" <span class="diff">}</span>
+</ins>
+}
+</pre>
+</div>
+<p>
+In
+the
+example
+above,
+every
+property
+is
+unambiguously
+identified
+by
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+and
+all
+values
+representing
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>
+are
+explicitly
+marked
+as
+such
+by
+the
+<code>
+@id
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>.
+While
+this
+is
+a
+valid
+JSON-LD
+document
+that
+is
+very
+specific
+about
+its
+data,
+the
+document
+is
+also
+overly
+verbose
+and
+difficult
+to
+work
+with
+for
+human
+developers.
+To
+address
+this
+issue,
+JSON-LD
+introduces
+the
+notion
+of
+a
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>
+as
+described
+in
+the
+next
+section.
+</p>
+<section id="the-context">
+<h3>
+<span class="secno">
+5.1
+</span>
+The
+Context
+</h3>
+<p>
+Simply
+speaking,
+a
+<dfn id="dfn-context" title="context">
+context
+</dfn>
+is
+used
+to
+map
+<a href="#dfn-term" title="term" class="tref internalDFN">
+terms
+</a>,
+i.e.,
+<a href="#dfn-property" title="property" class="tref internalDFN">
+properties
+</a>
+with
+associated
+values,
+to
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>.
+<a href="#dfn-term" title="term" class="tref internalDFN">
+Terms
+</a>
+are
+case
+sensitive
+and
+any
+valid
+<a href="#dfn-string" title="string" class="tref internalDFN">
+string
+</a>
+that
+is
+not
+a
+reserved
+JSON-LD
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>
+can
+be
+used
+as
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>.
+</p>
+<p>
+For
+the
+sample
+document
+in
+the
+previous
+section,
+a
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>
+would
+look
+something
+like
+this:
+</p>
+<del class="diff-old"> {
+ "@context":
+ {
+ "name": "http://schema.org/name",
+ "image": {
+ "@id": "http://schema.org/image",
+ "@type": "@id"
+ },
+ "homepage": {
+ "@id": "http://schema.org/url",
+ "@type": "@id"
+ }
+ }
+</del>
+ <div class="example"><div class="example-title"><span>Example 3</span>: Context for the sample document in the previous section</div><pre class="example">{
+ <span class="diff">"@context":
+<ins class="diff-chg"> {
+ "name": "http://schema.org/name",
+ "image": {
+ "@id": "http://schema.org/image",
+ "@type": "@id"
+ },
+ "homepage": {
+ "@id": "http://schema.org/url",
+ "@type": "@id"
+ }
+ }</span>
+</ins>
+}
+</pre>
+</div>
+<p>
+As
+the
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>
+above
+shows,
+the
+value
+of
+a
+<dfn id="dfn-term-definition" title="term-definition">
+term
+definition
+</dfn>
+can
+either
+be
+a
+simple
+string,
+mapping
+the
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+to
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+or
+a
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>.
+</p>
+<p>
+When
+a
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+is
+associated
+with
+a
+term,
+it
+is
+called
+an
+<a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">
+expanded
+term
+definition
+</a>.
+<dfn id="dfn-expanded-term-definition" title="expanded-term-definition">
+Expanded
+term
+definitions
+</dfn>
+may
+be
+used
+to
+associate
+<a href="#type-coercion">
+type
+</a>
+or
+<a href="#string-internationalization">
+language
+information
+</a>
+with
+a
+term.
+The
+example
+above
+specifies
+that
+the
+values
+of
+<code>
+image
+</code>
+and
+<code>
+homepage
+</code>
+terms
+are
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>.
+They
+also
+allow
+terms
+to
+be
+used
+for
+<a href="#data-indexing">
+index
+maps
+</a>
+and
+to
+specify
+whether
+<a href="#dfn-array" title="array" class="tref internalDFN">
+array
+</a>
+values
+are
+to
+be
+interpreted
+as
+<a href="#sets-and-lists">
+sets
+or
+lists
+</a>.
+<a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">
+Expanded
+term
+definitions
+</a>
+may
+be
+defined
+using
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+</a>
+or
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+IRIs
+</a>
+as
+keys,
+which
+is
+mainly
+used
+to
+associate
+type
+or
+language
+information
+with
+an
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+</a>
+or
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>.
+</p>
+<p>
+<a href="#dfn-context" title="context" class="tref internalDFN">
+Contexts
+</a>
+can
+either
+be
+directly
+embedded
+into
+the
+document
+or
+be
+referenced.
+Assuming
+the
+context
+document
+in
+the
+previous
+example
+can
+be
+retrieved
+at
+<code>
+http://json-ld.org/contexts/person.jsonld
+</code>,
+it
+can
+be
+referenced
+by
+adding
+a
+single
+line
+and
+allows
+a
+JSON-LD
+document
+to
+be
+expressed
+much
+more
+concisely
+as
+shown
+in
+the
+example
+below:
+</p>
+<del class="diff-old"> {
+
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/",
+ "image": "http://manu.sporny.org/images/manu.png"
+</del>
+ <div class="example"><div class="example-title"><span>Example 4</span>: Referencing a JSON-LD context</div><pre class="example">{
+ <span class="diff">"@context": "http://json-ld.org/contexts/person.jsonld",</span>
+<ins class="diff-chg"> "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/",
+ "image": "http://manu.sporny.org/images/manu.png"
+</ins>
+}
+</pre>
+</div>
+<p>
+The
+referenced
+context
+not
+only
+specifies
+how
+the
+terms
+map
+to
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>
+in
+the
+Schema.org
+vocabulary
+but
+also
+specifies
+that
+the
+values
+of
+the
+<code>
+homepage
+</code>
+and
+<code>
+image
+</code>
+property
+can
+be
+interpreted
+as
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+<del class="diff-old">(e.g.
+</del>
+<ins class="diff-chg">(
+</ins>
+<code>
+"@type":
+"@id"
+</code>,
+see
+section
+<a class="sec-ref" href="#iris">
+<span class="secno">
+5.2
+</span>
+<span class="sec-title">
+IRIs
+</span>
+</a>
+for
+more
+details).
+This
+information
+gives
+the
+data
+global
+context
+and
+allows
+developers
+to
+re-use
+each
+other's
+data
+without
+having
+to
+agree
+to
+how
+their
+data
+will
+interoperate
+on
+a
+site-by-site
+basis.
+External
+JSON-LD
+context
+documents
+may
+contain
+extra
+information
+located
+outside
+of
+the
+<code>
+@context
+</code>
+key,
+such
+as
+documentation
+about
+the
+<a href="#dfn-term" title="term" class="tref internalDFN">
+terms
+</a>
+declared
+in
+the
+document.
+Information
+contained
+outside
+of
+the
+<code>
+@context
+</code>
+value
+is
+ignored
+when
+the
+document
+is
+used
+as
+an
+external
+JSON-LD
+context
+document.
+</p>
+<p>
+Contexts
+may
+also
+be
+specified
+in-line.
+This
+has
+the
+advantage
+that
+<a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">
+JSON-LD
+documents
+</a>
+can
+be
+processed
+even
+in
+the
+absence
+of
+a
+connection
+to
+the
+Web.
+</p>
+<del class="diff-old"> {
+ "@context":
+ {
+ "name": "http://schema.org/name",
+ "image": {
+ "@id": "http://schema.org/image",
+ "@type": "@id"
+ },
+ "homepage": {
+ "@id": "http://schema.org/url",
+ "@type": "@id"
+ }
+ },
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/",
+ "image": "http://manu.sporny.org/images/manu.png"
+</del>
+ <div class="example"><div class="example-title"><span>Example 5</span>: In-line context definition</div><pre class="example">{
+ <span class="diff">"@context":
+<ins class="diff-chg"> {
+ "name": "http://schema.org/name",
+ "image": {
+ "@id": "http://schema.org/image",
+ "@type": "@id"
+ },
+ "homepage": {
+ "@id": "http://schema.org/url",
+ "@type": "@id"
+ }
+ },</span>
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/",
+ "image": "http://manu.sporny.org/images/manu.png"
+</ins>
+}
+</pre>
+</div>
+</section>
+<section id="iris">
+<h3>
+<span class="secno">
+5.2
+</span>
+IRIs
+</h3>
+<p>
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>
+(Internationalized
+Resource
+Identifiers
+[
+<cite>
+<a href="#bib-RFC3987" class="bibref">
+RFC3987
+</a>
+</cite>
+])
+are
+fundamental
+to
+<a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">
+Linked
+Data
+</a>
+as
+that
+is
+how
+most
+<a href="#dfn-node" title="node" class="tref internalDFN">
+nodes
+</a>
+and
+<a href="#dfn-property" title="property" class="tref internalDFN">
+properties
+</a>
+are
+identified.
+In
+JSON-LD,
+IRIs
+may
+be
+represented
+as
+an
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+or
+a
+<a href="#dfn-relative-iri" title="relative-iri" class="tref internalDFN">
+relative
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>.
+An
+<dfn id="dfn-absolute-iri" title="absolute-iri">
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</dfn>
+is
+defined
+in
+[
+<cite>
+<a href="#bib-RFC3987" class="bibref">
+RFC3987
+</a>
+</cite>
+]
+as
+containing
+a
+<em>
+scheme
+</em>
+along
+with
+<em>
+path
+</em>
+and
+optional
+<em>
+query
+</em>
+and
+<em>
+fragment
+</em>
+segments.
+A
+<dfn id="dfn-relative-iri" title="relative-iri">
+relative
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</dfn>
+is
+an
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+that
+is
+relative
+to
+some
+other
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>.
+In
+JSON-LD
+all
+<a href="#dfn-relative-iri" title="relative-iri" class="tref internalDFN">
+relative
+IRIs
+</a>
+are
+resolved
+relative
+to
+the
+<dfn id="dfn-base-iri" title="base-iri">
+base
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</dfn>
+associated
+with
+the
+document,
+which
+is
+typically
+the
+directory
+path
+containing
+the
+document.
+</p>
+<p>
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+IRIs
+</a>
+can
+be
+expressed
+directly
+in
+the
+key
+position
+like
+so:
+</p>
+<del class="diff-old"> {
+...
+ "": "Manu Sporny",
+...
+</del>
+ <div class="example"><div class="example-title"><span>Example 6</span>: IRI as a key</div><pre class="example">{
+<ins class="diff-chg">...
+ "<span class="diff">http://schema.org/name</span>": "Manu Sporny",
+...
+</ins>
+}
+</pre>
+</div>
+<p>
+In
+the
+example
+above,
+the
+key
+<code>
+http://schema.org/name
+</code>
+is
+interpreted
+as
+an
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+because
+it
+contains
+a
+colon
+(
+<code>:
+</code>
+)
+and
+the
+"http"
+<a href="#dfn-prefix" title="prefix" class="tref internalDFN">
+prefix
+</a>
+does
+not
+exist
+in
+the
+context.
+</p>
+<p>
+Term-to-
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+expansion
+occurs
+if
+the
+key
+matches
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+defined
+within
+the
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>:
+</p>
+<del class="diff-old"> {
+ "":
+ {
+ ""
+...
+ },
+ "": "Manu Sporny",
+ "status": "trollin'",
+...
+</del>
+ <div class="example"><div class="example-title"><span>Example 7</span>: Term expansion from context definition</div><pre class="example">{
+<ins class="diff-chg"> "<span class="diff">@context</span>":
+ {
+ "<span class="diff">name</span>": "<span class="diff">http://schema.org/name</span>"
+...
+ },
+ "<span class="diff">name</span>": "Manu Sporny",
+ "status": "trollin'",
+...
+</ins>
+}
+</pre>
+</div>
+<p>
+JSON
+keys
+that
+do
+not
+expand
+to
+an
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+are
+ignored,
+or
+removed
+in
+some
+cases,
+by
+the
+[
+<cite>
+<a href="#bib-JSON-LD-API" class="bibref">
+JSON-LD-API
+</a>
+</cite>
+].
+However,
+JSON
+keys
+that
+do
+not
+include
+a
+mapping
+in
+the
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>
+are
+still
+considered
+valid
+expressions
+in
+JSON-LD
+documents—the
+keys
+just
+don't
+expand
+to
+unambiguous
+identifiers.
+</p>
+<p>
+At
+times,
+all
+properties
+and
+types
+may
+come
+from
+the
+same
+vocabulary.
+JSON-LD's
+<code>
+@vocab
+</code>
+keyword
+allows
+an
+author
+to
+set
+a
+common
+prefix
+to
+be
+used
+for
+all
+properties
+and
+types
+that
+do
+not
+match
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+or
+are
+neither
+a
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+nor
+an
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+(i.e.,
+they
+do
+not
+contain
+a
+colon).
+</p>
+<del class="diff-old"> {
+ "@context": {
+ "@vocab": "http://schema.org/"
+ },
+ "@type": ,
+ : "Manu Sporny",
+</del>
+ <div class="example"><div class="example-title"><span>Example 8</span>: Using a common vocabulary prefix</div><pre class="example">{
+ <span class="diff">"@context": {
+<ins class="diff-chg"> "@vocab": "http://schema.org/"
+ },</span>
+ "@type": <span class="diff">"Person"</span>,
+</ins> <span class="diff">"name"</span>: "Manu Sporny",
+}
+</pre>
+</div>
+<p>
+An
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+is
+generated
+when
+a
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+is
+used
+in
+the
+value
+position
+and
+contains
+an
+<code>
+@id
+</code>
+keyword:
+</p>
+<del class="diff-old"> {
+...
+ "homepage": { "": "http://manu.sporny.org" }
+...
+</del>
+ <div class="example"><div class="example-title"><span>Example 9</span>: Expanded IRI definition</div><pre class="example">{
+<ins class="diff-chg">...
+ "homepage": { "<span class="diff">@id</span>": "http://manu.sporny.org" }
+...
+</ins>
+}
+</pre>
+</div>
+<p>
+Specifying
+a
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+with
+an
+<code>
+@id
+</code>
+key
+is
+used
+to
+identify
+that
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>
+using
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>.
+This
+facility
+may
+also
+be
+used
+to
+link
+to
+another
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>
+using
+a
+mechanism
+called
+<a href="#dfn-embedding" title="embedding" class="tref internalDFN">
+embedding
+</a>,
+which
+is
+covered
+in
+the
+section
+titled
+<a class="sec-ref" href="#embedding">
+<span class="secno">
+<del class="diff-old">6.10
+</del>
+<ins class="diff-chg">6.11
+</ins>
+</span>
+<span class="sec-title">
+Embedding
+</span>
+</a>.
+</p>
+<p>
+If
+type
+<a href="#dfn-coercion" title="coercion" class="tref internalDFN">
+coercion
+</a>
+rules
+are
+specified
+in
+the
+<code>
+@context
+</code>
+for
+a
+particular
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+or
+property
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>,
+an
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+is
+generated:
+</p>
+<del class="diff-old">
+ "@context":
+ {
+ ...
+ "homepage":
+ {
+ "@id": "http://schema.org/homepage",
+ "@type": "@id"
+ }
+ ...
+ }
+...
+ "homepage": "http://manu.sporny.org/",
+...
+</del>
+ <div class="example"><div class="example-title"><span>Example 10</span>: Type coercion</div><pre class="example">{<span class="diff">
+<ins class="diff-chg"> "@context":
+ {
+ ...
+ "homepage":
+ {
+ "@id": "http://schema.org/homepage",
+ "@type": "@id"
+ }
+ ...
+ }</span>
+...
+ "homepage": "http://manu.sporny.org/",
+...
+</ins>
+}
+</pre>
+</div>
+<p>
+In
+the
+example
+above,
+even
+though
+the
+value
+<code>
+http://manu.sporny.org/
+</code>
+is
+expressed
+as
+a
+JSON
+<a href="#dfn-string" title="string" class="tref internalDFN">
+string
+</a>,
+the
+type
+<a href="#dfn-coercion" title="coercion" class="tref internalDFN">
+coercion
+</a>
+rules
+will
+transform
+the
+value
+into
+an
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+when
+generating
+the
+<a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">
+JSON-LD
+graph
+</a>.
+See
+<a class="sec-ref" href="#type-coercion">
+<span class="secno">
+6.3
+</span>
+<span class="sec-title">
+Type
+Coercion
+</span>
+</a>
+for
+more
+details
+about
+this
+feature.
+</p>
+<p>
+In
+summary,
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>
+can
+be
+expressed
+in
+a
+variety
+of
+different
+ways
+in
+JSON-LD:
+</p>
+<ol>
+<li>
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+keys
+that
+have
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+mapping
+in
+the
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>
+expand
+to
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+(only
+applies
+outside
+of
+the
+<a href="#dfn-context-definition" title="context-definition" class="tref internalDFN">
+context
+definition
+</a>
+).
+</li>
+<li>
+If
+there
+is
+a
+<code>
+@vocab
+</code>
+mapping
+in
+the
+active
+context,
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+keys
+without
+an
+explicit
+mapping
+in
+the
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>
+are
+expanded
+to
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>.
+</li>
+<li>
+An
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+is
+generated
+for
+the
+<a href="#dfn-string" title="string" class="tref internalDFN">
+string
+</a>
+value
+specified
+using
+<code>
+@id
+</code>
+or
+<code>
+@type
+</code>.
+</li>
+<li>
+An
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+is
+generated
+for
+the
+<a href="#dfn-string" title="string" class="tref internalDFN">
+string
+</a>
+value
+of
+any
+key
+for
+which
+there
+are
+<a href="#dfn-coercion" title="coercion" class="tref internalDFN">
+coercion
+</a>
+rules
+that
+contain
+a
+<code>
+@type
+</code>
+key
+that
+is
+set
+to
+a
+value
+of
+<code>
+@id
+</code>
+<ins class="diff-new">or
+</ins><code><ins class="diff-new">
+@vocab
+</ins>
+</code>.
+</li>
+</ol>
+</section>
+<section id="node-identifiers">
+<h3>
+<span class="secno">
+5.3
+</span>
+Node
+Identifiers
+</h3>
+<p>
+To
+be
+able
+to
+externally
+reference
+<a href="#dfn-node" title="node" class="tref internalDFN">
+nodes
+</a>
+in
+a
+<a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">
+graph
+</a>,
+it
+is
+important
+that
+each
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>
+<del class="diff-old">have
+</del>
+<ins class="diff-chg">has
+</ins>
+an
+unambiguous
+identifier.
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>
+are
+a
+fundamental
+concept
+of
+<a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">
+Linked
+Data
+</a>,
+and
+<a href="#dfn-node" title="node" class="tref internalDFN">
+nodes
+</a>
+should
+have
+a
+de-referenceable
+identifier
+used
+to
+name
+and
+locate
+them.
+For
+<a href="#dfn-node" title="node" class="tref internalDFN">
+nodes
+</a>
+to
+be
+truly
+linked,
+de-referencing
+the
+identifier
+should
+result
+in
+a
+representation
+of
+that
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>.
+Associating
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+with
+a
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>
+tells
+an
+application
+that
+it
+can
+fetch
+the
+resource
+associated
+with
+the
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+and
+get
+back
+a
+description
+of
+the
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>.
+</p>
+<p>
+<a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">
+JSON-LD
+documents
+</a>
+may
+also
+contain
+descriptions
+of
+other
+<a href="#dfn-node" title="node" class="tref internalDFN">
+nodes
+</a>,
+so
+it
+is
+necessary
+to
+be
+able
+to
+uniquely
+identify
+each
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>
+so
+that
+the
+data
+is
+associated
+with
+the
+correct
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>
+in
+an
+unambiguous
+way.
+</p>
+<p>
+A
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>
+is
+identified
+using
+the
+<code>
+@id
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>:
+</p>
+<del class="diff-old"> {
+ "@context":
+ {
+ ...
+ "homepage":
+ {
+ "@id": "http://schema.org/homepage",
+ "@type": "@id"
+ }
+ },
+ "",
+ "homepage": "http://joebob.example.com/",
+ ...
+</del>
+ <div class="example"><div class="example-title"><span>Example 11</span>: Identifying a node</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+ ...
+ "homepage":
+ {
+ "@id": "http://schema.org/homepage",
+ "@type": "@id"
+ }
+ },
+ "<span class="diff">@id</span>": "<span class="diff">http://example.org/people#joebob</span>",
+ "homepage": "http://joebob.example.com/",
+ ...
+</ins>
+}
+</pre>
+</div>
+<p>
+The
+example
+above
+contains
+a
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>
+identified
+by
+the
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+<code>
+http://example.org/people#joebob
+</code>.
+</p>
+</section>
+<section id="specifying-the-type">
+<h3>
+<span class="secno">
+5.4
+</span>
+Specifying
+the
+Type
+</h3>
+<p>
+The
+type
+of
+a
+particular
+node
+can
+be
+specified
+using
+the
+<code>
+@type
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>.
+In
+<a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">
+Linked
+Data
+</a>,
+types
+are
+uniquely
+identified
+with
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>.
+</p>
+<del class="diff-old">{
+...
+ "@id": "http://example.org/places#BrewEats",
+ "",
+...
+</del>
+<div class="example"><div class="example-title"><span>Example 12</span>: Specifying the type for a node</div><pre class="example">{
+<ins class="diff-chg">...
+ "@id": "http://example.org/places#BrewEats",
+ "<span class="diff">@type</span>": "<span class="diff">http://schema.org/Restaurant</span>",
+...
+</ins>
+}
+</pre>
+</div>
+<p>
+A
+node
+can
+be
+assigned
+more
+than
+one
+type
+by
+using
+an
+<a href="#dfn-array" title="array" class="tref internalDFN">
+array
+</a>:
+</p>
+<del class="diff-old">{
+...
+ "@id": "http://example.org/places#BrewEats",
+ "
+...
+</del>
+<div class="example"><div class="example-title"><span>Example 13</span>: Specifying multiple types for a node</div><pre class="example">{
+<ins class="diff-chg">...
+ "@id": "http://example.org/places#BrewEats",
+ "<span class="diff">@type</span>": <span class="diff">[ "http://schema.org/Restaurant", "http://schema.org/Brewery" ],</span>
+...
+</ins>
+}
+</pre>
+</div>
+<p>
+The
+value
+of
+a
+<code>
+@type
+</code>
+key
+may
+also
+be
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+defined
+in
+the
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>:
+</p>
+<del class="diff-old">{
+ "@context": {
+ ...
+
+
+ }
+ "@id": "http://example.org/places#BrewEats",
+ ,
+ ...
+</del>
+<div class="example"><div class="example-title"><span>Example 14</span>: Using a term to specify the type</div><pre class="example">{
+<ins class="diff-chg"> "@context": {
+ ...
+</ins> <span class="diff">"Restaurant": "http://schema.org/Restaurant", </span>
+ <span class="diff">"Brewery": "http://schema.org/Brewery"</span>
+<ins class="diff-chg">
+ }
+ "@id": "http://example.org/places#BrewEats",
+</ins> <span class="diff">"@type": ["Restaurant", "Brewery"]</span>,
+<ins class="diff-chg">
+ ...
+</ins>
+}
+</pre>
+</div>
+</section>
+</section>
+<section id="advanced-concepts">
+<h2>
+<span class="secno">
+6.
+</span>
+Advanced
+Concepts
+</h2>
+<em>
+This
+section
+is
+normative.
+</em>
+<p>
+JSON-LD
+has
+a
+number
+of
+features
+that
+provide
+functionality
+above
+and
+beyond
+the
+core
+functionality
+described
+above.
+The
+following
+section
+describes
+this
+advanced
+functionality
+in
+more
+detail.
+</p>
+<section id="compact-iris">
+<h3>
+<span class="secno">
+6.1
+</span>
+Compact
+IRIs
+</h3>
+<p>
+A
+document
+on
+the
+Web
+that
+defines
+one
+or
+more
+IRIs
+for
+use
+as
+<a href="#dfn-property" title="property" class="tref internalDFN">
+properties
+</a>
+in
+Linked
+Data
+is
+called
+a
+<dfn id="dfn-vocabulary" title="vocabulary">
+vocabulary
+</dfn>.
+<a href="#dfn-term" title="term" class="tref internalDFN">
+Terms
+</a>
+in
+<a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">
+Linked
+Data
+</a>
+documents
+may
+draw
+from
+a
+number
+of
+different
+<a href="#dfn-vocabulary" title="vocabulary" class="tref internalDFN">
+vocabularies
+</a>
+s.
+At
+times,
+declaring
+every
+single
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+that
+a
+document
+uses
+can
+require
+the
+developer
+to
+declare
+tens,
+if
+not
+hundreds
+of
+potential
+vocabulary
+<a href="#dfn-term" title="term" class="tref internalDFN">
+terms
+</a>
+that
+are
+used
+across
+an
+application.
+This
+is
+a
+concern
+for
+at
+least
+two
+reasons:
+the
+first
+is
+the
+cognitive
+load
+on
+the
+developer
+of
+remembering
+all
+of
+the
+<a href="#dfn-term" title="term" class="tref internalDFN">
+terms
+</a>,
+and
+the
+second
+is
+the
+serialized
+size
+of
+the
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>
+if
+it
+is
+specified
+inline.
+In
+order
+to
+address
+these
+issues,
+the
+concept
+of
+a
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+is
+introduced.
+</p>
+<p>
+A
+<dfn id="dfn-compact-iri" title="compact-iri">
+compact
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</dfn>
+is
+a
+way
+of
+expressing
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+using
+a
+<em>
+prefix
+</em>
+and
+<em>
+suffix
+</em>
+separated
+by
+a
+colon
+(
+<code>:
+</code>
+)
+which
+is
+similar
+to
+the
+<cite>
+<a href="http://www.w3.org/TR/rdfa-core/#s_curies">
+CURIE
+Syntax
+</a>
+</cite>
+in
+[
+<cite>
+<a href="#bib-RDFA-CORE" class="bibref">
+RDFA-CORE
+</a>
+</cite>
+].
+The
+<dfn id="dfn-prefix" title="prefix">
+prefix
+</dfn>
+is
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+taken
+from
+the
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>
+and
+is
+a
+short
+string
+identifying
+a
+particular
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+in
+a
+JSON-LD
+document.
+For
+example,
+the
+prefix
+<code>
+foaf
+</code>
+may
+be
+used
+as
+a
+short
+hand
+for
+the
+Friend-of-a-Friend
+vocabulary,
+which
+is
+identified
+using
+the
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+<code>
+http://xmlns.com/foaf/0.1/
+</code>.
+A
+developer
+may
+append
+any
+of
+the
+FOAF
+vocabulary
+terms
+to
+the
+end
+of
+the
+prefix
+to
+specify
+a
+short-hand
+version
+of
+the
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+for
+the
+vocabulary
+term.
+For
+example,
+<code>
+foaf:name
+</code>
+would
+be
+expanded
+out
+to
+the
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+<code>
+http://xmlns.com/foaf/0.1/name
+</code>.
+Instead
+of
+having
+to
+remember
+and
+type
+out
+the
+entire
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>,
+the
+developer
+can
+instead
+use
+the
+prefix
+in
+their
+JSON-LD
+markup.
+</p>
+<p>
+<a href="#dfn-prefix" title="prefix" class="tref internalDFN">
+Prefixes
+</a>
+are
+expanded
+when
+the
+form
+of
+the
+value
+is
+a
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+represented
+as
+a
+<code>
+prefix:suffix
+</code>
+combination,
+and
+the
+prefix
+matches
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+defined
+within
+the
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>:
+</p>
+<del class="diff-old"> {
+ "":
+ {
+ ""
+...
+ },
+ "": "Dave Longley",
+...
+</del>
+ <div class="example"><div class="example-title"><span>Example 15</span>: Prefix expansion</div><pre class="example">{
+<ins class="diff-chg"> "<span class="diff">@context</span>":
+ {
+ "<span class="diff">foaf</span>": "<span class="diff">http://xmlns.com/foaf/0.1/</span>"
+...
+ },
+ "<span class="diff">foaf:name</span>": "Dave Longley",
+...
+</ins>
+}
+</pre>
+</div>
+<p>
+<code>
+foaf:name
+</code>
+above
+will
+automatically
+expand
+out
+to
+the
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+<code>
+http://xmlns.com/foaf/0.1/name
+</code>.
+</p>
+<p>
+Terms
+are
+interpreted
+as
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+IRIs
+</a>
+if
+they
+contain
+at
+least
+one
+colon
+and
+the
+first
+colon
+is
+not
+followed
+by
+two
+slashes
+(
+<code>
+//
+</code>,
+as
+in
+<code>
+http://example.com
+</code>
+).
+To
+generate
+the
+full
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+the
+value
+is
+first
+split
+into
+a
+<em>
+prefix
+</em>
+and
+<em>
+suffix
+</em>
+at
+the
+first
+occurrence
+of
+a
+colon
+(
+<code>:
+</code>
+).
+If
+the
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>
+contains
+a
+term
+mapping
+for
+<em>
+prefix
+</em>,
+an
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+is
+generated
+by
+prepending
+the
+mapped
+<em>
+prefix
+</em>
+to
+the
+(possibly
+empty)
+<em>
+suffix
+</em>
+using
+textual
+concatenation.
+If
+no
+prefix
+mapping
+is
+defined,
+the
+value
+is
+interpreted
+as
+an
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>.
+If
+the
+prefix
+is
+an
+underscore
+(
+<code>
+_
+</code>
+),
+the
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+remains
+unchanged.
+</p>
+<p>
+Consider
+the
+following
+example:
+</p>
+<del class="diff-old"> {
+ "@context":
+ {
+
+
+ },
+ "@id": "http://example.org/library",
+ "@type": ,
+ :
+ {
+ "@id": "http://example.org/library/the-republic",
+ "@type": ,
+ : "Plato",
+ : "The Republic",
+ :
+ {
+ "@id": "http://example.org/library/the-republic#introduction",
+ "@type": ,
+ : "An introductory chapter on The Republic.",
+ : "The Introduction"
+ }
+ }
+</del>
+ <div class="example"><div class="example-title"><span>Example 16</span>: Compact IRIs</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+</ins> <span class="diff">"dc": "http://purl.org/dc/elements/1.1/",</span>
+ <span class="diff">"ex": "http://example.org/vocab#"</span>
+<ins class="diff-chg">
+ },
+ "@id": "http://example.org/library",
+ "@type": <span class="diff">"ex:Library"</span>,
+</ins> <span class="diff">"ex:contains"</span>:
+<ins class="diff-chg">
+ {
+ "@id": "http://example.org/library/the-republic",
+ "@type": <span class="diff">"ex:Book"</span>,
+</ins> <span class="diff">"dc:creator"</span>: "Plato",
+ <span class="diff">"dc:title"</span>: "The Republic",
+ <span class="diff">"ex:contains"</span>:
+<ins class="diff-chg">
+ {
+ "@id": "http://example.org/library/the-republic#introduction",
+ "@type": <span class="diff">"ex:Chapter"</span>,
+</ins> <span class="diff">"dc:description"</span>: "An introductory chapter on The Republic.",
+ <span class="diff">"dc:title"</span>: "The Introduction"
+<ins class="diff-chg">
+ }
+ }
+</ins>
+}
+</pre>
+</div>
+<p>
+In
+this
+example,
+two
+different
+vocabularies
+are
+referred
+to
+using
+prefixes.
+Those
+prefixes
+are
+then
+used
+as
+type
+and
+property
+values
+using
+the
+compact
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+<code>
+prefix:suffix
+</code>
+notation.
+</p>
+<p>
+It's
+also
+possible
+to
+use
+compact
+IRIs
+within
+the
+context
+as
+shown
+in
+the
+following
+example:
+</p>
+<del class="diff-old"> {
+ "@context":
+ {
+ "xsd": "http://www.w3.org/2001/XMLSchema#",
+ ,
+ : { "@type": "@id" },
+ "picture": { "@id": , "@type": "@id" }
+ },
+ "@id": "http://me.markus-lanthaler.com/",
+ "@type": "foaf:Person",
+ "foaf:name": "Markus Lanthaler",
+ "foaf:homepage": "http://www.markus-lanthaler.com/",
+ "picture": "http://twitter.com/account/profile_image/markuslanthaler"
+</del>
+ <div class="example"><div class="example-title"><span>Example 17</span>: Using vocabularies</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+ "xsd": "http://www.w3.org/2001/XMLSchema#",
+</ins> <span class="diff">"foaf": "http://xmlns.com/foaf/0.1/"</span>,
+ <span class="diff">"foaf:homepage"</span>: { "@type": "@id" },
+<ins class="diff-chg">
+ "picture": { "@id": <span class="diff">"foaf:depiction"</span>, "@type": "@id" }
+ },
+ "@id": "http://me.markus-lanthaler.com/",
+ "@type": "foaf:Person",
+ "foaf:name": "Markus Lanthaler",
+ "foaf:homepage": "http://www.markus-lanthaler.com/",
+ "picture": "http://twitter.com/account/profile_image/markuslanthaler"
+</ins>
+}
+</pre>
+</div>
+</section>
+<section id="typed-values">
+<h3>
+<span class="secno">
+6.2
+</span>
+Typed
+Values
+</h3>
+<p>
+A
+value
+with
+an
+associated
+type,
+also
+known
+as
+a
+<a href="#dfn-typed-value" title="typed-value" class="tref internalDFN">
+typed
+value
+</a>,
+is
+indicated
+by
+associating
+a
+value
+with
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+which
+indicates
+the
+value's
+type.
+Typed
+values
+may
+be
+expressed
+in
+JSON-LD
+in
+three
+ways:
+</p>
+<ol>
+<li>
+By
+utilizing
+the
+<code>
+@type
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>
+when
+defining
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+within
+a
+<code>
+@context
+</code>
+section.
+</li>
+<li>
+By
+utilizing
+an
+<a href="#dfn-expanded-typed-value" title="expanded-typed-value" class="tref internalDFN">
+expanded
+typed
+value
+</a>.
+</li>
+<li>
+By
+using
+a
+native
+JSON
+type
+such
+as
+<a href="#dfn-number" title="number" class="tref internalDFN">
+number
+</a>,
+<a href="#dfn-true" title="true" class="tref internalDFN">
+true
+</a>,
+or
+<a href="#dfn-false" title="false" class="tref internalDFN">
+false
+</a>.
+</li>
+</ol>
+<p>
+The
+first
+example
+uses
+the
+<code>
+@type
+</code>
+keyword
+to
+associate
+a
+type
+with
+a
+particular
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+in
+the
+<code>
+@context
+</code>:
+</p>
+<del class="diff-old">{
+ "@context":
+ {
+ "modified":
+ {
+ "@id": "http://purl.org/dc/terms/modified",
+ "@type": "http://www.w3.org/2001/XMLSchema#dateTime"
+ }
+ },
+...
+ "@id": "http://example.com/docs/1",
+ "modified": "2010-05-29T14:17:39+02:00",
+...
+</del>
+<div class="example"><div class="example-title"><span>Example 18</span>: Expanded term definition with type coercion</div><pre class="example">{
+ <span class="diff">"@context":
+<ins class="diff-chg"> {
+ "modified":
+ {
+ "@id": "http://purl.org/dc/terms/modified",
+ "@type": "http://www.w3.org/2001/XMLSchema#dateTime"
+ }
+ },</span>
+...
+ "@id": "http://example.com/docs/1",
+ "modified": "2010-05-29T14:17:39+02:00",
+...
+</ins>
+}
+</pre>
+</div>
+<p>
+The
+<em>
+modified
+</em>
+key's
+value
+above
+is
+automatically
+type
+coerced
+to
+a
+dateTime
+value
+because
+of
+the
+information
+specified
+in
+the
+<code>
+@context
+</code>.
+A
+JSON-LD
+processor
+will
+interpret
+the
+markup
+above
+like
+so:
+</p>
+<table class="example">
+<thead>
+<tr>
+<th>
+Subject
+</th>
+<th>
+Property
+</th>
+<th>
+Value
+</th>
+<th>
+Value
+Type
+</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>
+http://example.com/docs/1
+</td>
+<td>
+http://purl.org/dc/terms/modified
+</td>
+<td>
+2010-05-29T14:17:39+02:00
+</td>
+<td>
+http://www.w3.org/2001/XMLSchema#dateTime
+</td>
+</tr>
+</tbody>
+</table>
+<p>
+The
+second
+example
+uses
+the
+expanded
+form
+of
+setting
+the
+type
+information
+in
+the
+body
+of
+a
+JSON-LD
+document:
+</p>
+<del class="diff-old">{
+ "@context":
+ {
+ "modified":
+ {
+ "@id": "http://purl.org/dc/terms/modified"
+ }
+ },
+...
+ "modified":
+ {
+ "@value": "2010-05-29T14:17:39+02:00",
+ "@type": "http://www.w3.org/2001/XMLSchema#dateTime"
+ }
+...
+</del>
+<div class="example"><div class="example-title"><span>Example 19</span>: Expanded value with type</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+ "modified":
+ {
+ "@id": "http://purl.org/dc/terms/modified"
+ }
+ },
+...
+ "modified":
+</ins> <span class="diff">{
+<ins class="diff-chg">
+ "@value": "2010-05-29T14:17:39+02:00",
+ "@type": "http://www.w3.org/2001/XMLSchema#dateTime"
+ }</span>
+...
+</ins>
+}
+</pre>
+</div>
+<p>
+Both
+examples
+above
+would
+generate
+the
+value
+<code>
+2010-05-29T14:17:39+02:00
+</code>
+with
+the
+type
+<code>
+http://www.w3.org/2001/XMLSchema#dateTime
+</code>.
+Note
+that
+it
+is
+also
+possible
+to
+use
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+or
+a
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+to
+express
+the
+value
+of
+a
+type.
+</p>
+<p>
+The
+<code>
+@type
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>
+is
+also
+used
+to
+associate
+a
+type
+with
+a
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>.
+The
+concept
+of
+a
+<a href="#dfn-node-type" title="node-type" class="tref internalDFN">
+node
+type
+</a>
+and
+a
+<a href="#dfn-value-type" title="value-type" class="tref internalDFN">
+value
+type
+</a>
+are
+different.
+</p>
+<p>
+Generally
+speaking,
+a
+<dfn id="dfn-node-type" title="node-type">
+node
+type
+</dfn>
+specifies
+the
+type
+of
+thing
+that
+is
+being
+described,
+like
+a
+person,
+place,
+event,
+or
+web
+page.
+A
+<dfn id="dfn-value-type" title="value-type">
+value
+type
+</dfn>
+specifies
+the
+unit
+of
+measurement
+for
+a
+particular
+value,
+such
+as
+a
+date,
+meter,
+or
+light
+year.
+</p>
+<del class="diff-old">{
+...
+ "@id": "http://example.org/posts#TripToWestVirginia",
+ , <--- This is a node type
+ "modified":
+ {
+ "@value": "2010-05-29T14:17:39+02:00",
+ <--- This is a value type
+ }
+...
+</del>
+<div class="example"><div class="example-title"><span>Example 20</span>: Example demonstrating the context-sensitivity for @type</div><pre class="example">{
+<ins class="diff-chg">...
+ "@id": "http://example.org/posts#TripToWestVirginia",
+</ins> <span class="diff">"@type": "http://schema.org/BlogPosting"</span>, <--- This is a node type
+<ins class="diff-chg">
+ "modified":
+ {
+ "@value": "2010-05-29T14:17:39+02:00",
+</ins> <span class="diff">"@type": "http://www.w3.org/2001/XMLSchema#dateTime"</span> <--- This is a value type
+<ins class="diff-chg">
+ }
+...
+</ins>
+}
+</pre>
+</div>
+<p>
+The
+first
+use
+of
+<code>
+@type
+</code>
+associates
+a
+<a href="#dfn-node-type" title="node-type" class="tref internalDFN">
+node
+type
+</a>
+(
+<code>
+http://schema.org/BlogPosting
+</code>
+)
+with
+the
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>,
+which
+is
+expressed
+using
+the
+<code>
+@id
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>.
+The
+second
+use
+of
+<code>
+@type
+</code>
+associates
+a
+<a href="#dfn-value-type" title="value-type" class="tref internalDFN">
+value
+type
+</a>
+(
+<code>
+http://www.w3.org/2001/XMLSchema#dateTime
+</code>
+)
+with
+the
+value
+expressed
+using
+the
+<code>
+@value
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>.
+As
+a
+general
+rule,
+when
+<code>
+@value
+</code>
+and
+<code>
+@type
+</code>
+are
+used
+in
+the
+same
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>,
+the
+<code>
+@type
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>
+is
+expressing
+a
+<a href="#dfn-value-type" title="value-type" class="tref internalDFN">
+value
+type
+</a>.
+Otherwise,
+the
+<code>
+@type
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>
+is
+expressing
+a
+<a href="#dfn-node-type" title="node-type" class="tref internalDFN">
+node
+type
+</a>.
+The
+markup
+above
+expresses
+the
+following
+data:
+</p>
+<table class="example">
+<thead>
+<tr>
+<th>
+Subject
+</th>
+<th>
+Property
+</th>
+<th>
+Value
+</th>
+<th>
+Value
+Type
+</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>
+http://example.org/posts#TripToWestVirginia
+</td>
+<td>
+http://www.w3.org/1999/02/22-rdf-syntax-ns#type
+</td>
+<td>
+http://schema.org/BlogPosting
+</td>
+<td style="text-align:center;">
+-
+</td>
+</tr>
+<tr>
+<td>
+http://example.org/posts#TripToWestVirginia
+</td>
+<td>
+http://purl.org/dc/terms/modified
+</td>
+<td>
+2010-05-29T14:17:39+02:00
+</td>
+<td>
+http://www.w3.org/2001/XMLSchema#dateTime
+</td>
+</tr>
+</tbody>
+</table>
+</section>
+<section id="type-coercion">
+<h3>
+<span class="secno">
+6.3
+</span>
+Type
+Coercion
+</h3>
+<p>
+JSON-LD
+supports
+the
+coercion
+of
+values
+to
+particular
+data
+types.
+Type
+<dfn id="dfn-coercion" title="coercion">
+coercion
+</dfn>
+allows
+someone
+deploying
+JSON-LD
+to
+coerce
+the
+incoming
+or
+outgoing
+values
+to
+the
+proper
+data
+type
+based
+on
+a
+mapping
+of
+data
+type
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>
+to
+<a href="#dfn-term" title="term" class="tref internalDFN">
+terms
+</a>.
+Using
+type
+coercion,
+value
+representation
+is
+preserved
+without
+requiring
+the
+data
+type
+to
+be
+specified
+with
+each
+piece
+of
+data.
+</p>
+<p>
+Type
+coercion
+is
+specified
+within
+an
+<a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">
+expanded
+term
+definition
+</a>
+using
+the
+<code>
+@type
+</code>
+key.
+The
+value
+of
+this
+key
+expands
+to
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>.
+Alternatively,
+the
+<del class="diff-old">keyword
+</del>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+<ins class="diff-chg">keywords
+</ins>
+</a>
+<code>
+@id
+</code>
+<ins class="diff-new">or
+</ins><code><ins class="diff-new">
+@vocab
+</ins></code>
+may
+be
+used
+as
+value
+to
+indicate
+that
+within
+the
+body
+of
+a
+JSON-LD
+document,
+a
+<a href="#dfn-string" title="string" class="tref internalDFN">
+string
+</a>
+value
+of
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+coerced
+to
+<code>
+@id
+</code>
+<ins class="diff-new">or
+</ins><code><ins class="diff-new">
+@vocab
+</ins></code>
+is
+to
+be
+interpreted
+as
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>.
+<ins class="diff-new">The
+difference
+between
+</ins><code><ins class="diff-new">
+@id
+</ins></code><ins class="diff-new">
+and
+</ins><code><ins class="diff-new">
+@vocab
+</ins></code><ins class="diff-new">
+is
+how
+values
+are
+expanded
+to
+</ins><a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN"><ins class="diff-new">
+absolute
+IRIs
+</ins></a>.<code><ins class="diff-new">
+@vocab
+</ins></code><ins class="diff-new">
+first
+tries
+to
+expand
+the
+value
+by
+interpreting
+it
+as
+</ins><a href="#dfn-term" title="term" class="tref internalDFN"><ins class="diff-new">
+term
+</ins></a>.<ins class="diff-new">
+If
+no
+matching
+</ins><a href="#dfn-term" title="term" class="tref internalDFN"><ins class="diff-new">
+term
+</ins></a><ins class="diff-new">
+is
+found
+in
+the
+</ins><a href="#dfn-active-context" title="active-context" class="tref internalDFN"><ins class="diff-new">
+active
+context
+</ins></a>,<ins class="diff-new">
+it
+tries
+to
+expand
+it
+as
+</ins><a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN"><ins class="diff-new">
+compact
+</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
+IRI
+</ins></abbr></a><ins class="diff-new">
+or
+</ins><a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN"><ins class="diff-new">
+absolute
+</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
+IRI
+</ins></abbr></a><ins class="diff-new">
+if
+there's
+a
+colon
+in
+the
+value;
+otherwise,
+it
+will
+expand
+the
+value
+using
+the
+</ins><a href="#dfn-active-context" title="active-context" class="tref internalDFN"><ins class="diff-new">
+active
+context's
+</ins></a><ins class="diff-new">
+vocabulary
+mapping,
+if
+present,
+or
+by
+interpreting
+it
+as
+</ins><a href="#dfn-relative-iri" title="relative-iri" class="tref internalDFN"><ins class="diff-new">
+relative
+</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
+IRI
+</ins></abbr></a>.<ins class="diff-new">
+Values
+coerced
+to
+</ins><code><ins class="diff-new">
+@id
+</ins></code><ins class="diff-new">
+in
+contrast
+are
+expanded
+as
+</ins><a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN"><ins class="diff-new">
+compact
+</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
+IRI
+</ins></abbr></a><ins class="diff-new">
+or
+</ins><a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN"><ins class="diff-new">
+absolute
+</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
+IRI
+</ins></abbr></a><ins class="diff-new">
+if
+a
+colon
+is
+present;
+otherwise,
+they
+are
+interpreted
+as
+</ins><a href="#dfn-relative-iri" title="relative-iri" class="tref internalDFN"><ins class="diff-new">
+relative
+</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
+IRI
+</ins></abbr></a>.
+</p>
+<p>
+<a href="#dfn-term" title="term" class="tref internalDFN">
+Terms
+</a>
+or
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+IRIs
+</a>
+used
+as
+the
+value
+of
+a
+<code>
+@type
+</code>
+key
+may
+be
+defined
+within
+the
+same
+context.
+This
+means
+that
+one
+may
+specify
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+like
+<code>
+xsd
+</code>
+and
+then
+use
+<code>
+xsd:integer
+</code>
+within
+the
+same
+context
+definition.
+</p>
+<p>
+The
+example
+below
+demonstrates
+how
+a
+JSON-LD
+author
+can
+coerce
+values
+to
+<a href="#dfn-typed-value" title="typed-value" class="tref internalDFN">
+typed
+values
+</a>,
+IRIs,
+and
+lists.
+</p>
+<del class="diff-old">{
+ "@context":
+ {
+ "xsd": "http://www.w3.org/2001/XMLSchema#",
+ "name": "http://xmlns.com/foaf/0.1/name",
+ "age":
+ {
+ "@id": "http://xmlns.com/foaf/0.1/age",
+ "@type": "xsd:integer"
+ },
+ "homepage":
+ {
+ "@id": "http://xmlns.com/foaf/0.1/homepage",
+ "@type": "@id",
+ "@container": "@list"
+ }
+ },
+ "@id": "http://example.com/people#john",
+ "name": "John Smith",
+ "age": ,
+ "homepage":
+ [
+ "http://personal.example.org/",
+ "http://work.example.com/jsmith/"
+ ]
+</del>
+<div class="example"><div class="example-title"><span>Example 21</span>: Expanded term definition with types</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+ "xsd": "http://www.w3.org/2001/XMLSchema#",
+ "name": "http://xmlns.com/foaf/0.1/name",
+ "age":
+</ins> <span class="diff">{
+<ins class="diff-chg">
+ "@id": "http://xmlns.com/foaf/0.1/age",
+ "@type": "xsd:integer"
+ }</span>,
+ "homepage":
+</ins> <span class="diff">{
+<ins class="diff-chg">
+ "@id": "http://xmlns.com/foaf/0.1/homepage",
+ "@type": "@id",
+ "@container": "@list"
+ }</span>
+ },
+ "@id": "http://example.com/people#john",
+ "name": "John Smith",
+ "age": <span class="diff">"41"</span>,
+ "homepage":
+</ins> <span class="diff">[
+<ins class="diff-chg">
+ "http://personal.example.org/",
+ "http://work.example.com/jsmith/"
+ ]</span>
+</ins>
+}
+</pre>
+</div>
+<p>
+The
+markup
+shown
+above
+would
+generate
+the
+following
+data.
+The
+data
+has
+no
+inherent
+order
+except
+for
+the
+values
+of
+the
+<code>
+http://schema.org/homepage
+</code>
+property
+which
+represent
+an
+ordered
+list.
+</p>
+<table class="example">
+<thead>
+<tr>
+<th>
+Subject
+</th>
+<th>
+Property
+</th>
+<th>
+Value
+</th>
+<th>
+Value
+Type
+</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>
+http://example.com/people#john
+</td>
+<td>
+http://xmlns.com/foaf/0.1/name
+</td>
+<td>
+John
+Smith
+</td>
+<td>
+
+</td>
+</tr>
+<tr>
+<td>
+http://example.com/people#john
+</td>
+<td>
+http://xmlns.com/foaf/0.1/age
+</td>
+<td>
+41
+</td>
+<td>
+http://www.w3.org/2001/XMLSchema#integer
+</td>
+</tr>
+<tr>
+<td rowspan="2">
+http://example.com/people#john
+</td>
+<td rowspan="2">
+http://xmlns.com/foaf/0.1/homepage
+</td>
+<td>
+http://personal.example.org/
+</td>
+<td>
+
+</td>
+</tr>
+<tr>
+<td>
+http://work.example.com/jsmith/
+</td>
+<td>
+
+</td>
+</tr>
+</tbody>
+</table>
+<p>
+Terms
+may
+also
+be
+defined
+using
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+IRIs
+</a>
+or
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+IRIs
+</a>.
+This
+allows
+coercion
+rules
+to
+be
+applied
+to
+keys
+which
+are
+not
+represented
+as
+a
+simple
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>.
+For
+example:
+</p>
+<del class="diff-old">{
+ "@context":
+ {
+ "foaf": "http://xmlns.com/foaf/0.1/",
+ "":
+ {
+ ,
+ "@type": "xsd:integer"
+ },
+ "":
+ {
+ "@type": "@id"
+ }
+ },
+ "foaf:name": "John Smith",
+ "": "41",
+ "":
+ [
+ "http://personal.example.org/",
+ "http://work.example.com/jsmith/"
+ ]
+</del>
+<div class="example"><div class="example-title"><span>Example 22</span>: Term definitions using compact and absolute IRIs</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+ "foaf": "http://xmlns.com/foaf/0.1/",
+ "<span class="diff">foaf:age</span>":
+ {
+</ins> <span class="diff">"@id": "http://xmlns.com/foaf/0.1/age"</span>,
+<ins class="diff-chg">
+ "@type": "xsd:integer"
+ },
+ "<span class="diff">http://xmlns.com/foaf/0.1/homepage</span>":
+ {
+ "@type": "@id"
+ }
+ },
+ "foaf:name": "John Smith",
+ "<span class="diff">foaf:age</span>": "41",
+ "<span class="diff">http://xmlns.com/foaf/0.1/homepage</span>":
+ [
+ "http://personal.example.org/",
+ "http://work.example.com/jsmith/"
+ ]
+</ins>
+}
+</pre>
+</div>
+<p>
+In
+this
+case
+the
+<code>
+@id
+</code>
+definition
+in
+the
+term
+definition
+is
+optional,
+but
+if
+it
+does
+exist,
+the
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+or
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+is
+treated
+as
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+(not
+a
+<code>
+prefix:suffix
+</code>
+construct)
+so
+that
+the
+actual
+definition
+of
+a
+<a href="#dfn-prefix" title="prefix" class="tref internalDFN">
+prefix
+</a>
+becomes
+unnecessary.
+Type
+coercion
+is
+performed
+using
+the
+unexpanded
+value
+of
+the
+key
+if
+there
+is
+an
+exact
+match
+for
+the
+key
+in
+the
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>.
+</p>
+<div class="note">
+<div class="note-title">
+<span>
+Note
+</span>
+</div>
+<p class="">
+Keys
+in
+the
+context
+are
+treated
+as
+<a href="#dfn-term" title="term" class="tref internalDFN">
+terms
+</a>
+for
+the
+purpose
+of
+expansion
+and
+value
+coercion.
+At
+times,
+this
+may
+result
+in
+multiple
+representations
+for
+the
+same
+expanded
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>.
+For
+example,
+one
+could
+specify
+that
+<code>
+dog
+</code>
+and
+<code>
+cat
+</code>
+both
+expanded
+to
+<code>
+http://example.com/vocab#animal
+</code>.
+Doing
+this
+could
+be
+useful
+for
+establishing
+different
+type
+coercion
+or
+language
+specification
+rules.
+It
+also
+allows
+a
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+(or
+even
+an
+absolute
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+)
+to
+be
+defined
+as
+something
+else
+entirely.
+For
+example,
+one
+could
+specify
+that
+the
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+<code>
+http://example.org/zoo
+</code>
+should
+expand
+to
+<code>
+http://example.org/river
+</code>,
+but
+this
+usage
+is
+discouraged
+because
+it
+would
+lead
+to
+a
+great
+deal
+of
+confusion
+among
+developers
+attempting
+to
+understand
+the
+JSON-LD
+document.
+</p>
+</div>
+</section>
+<section id="advanced-context-usage">
+<h3>
+<span class="secno">
+6.4
+</span>
+Advanced
+Context
+Usage
+</h3>
+<p>
+Section
+<a class="sec-ref" href="#the-context">
+<span class="secno">
+5.1
+</span>
+<span class="sec-title">
+The
+Context
+</span>
+</a>
+introduced
+the
+basics
+of
+what
+makes
+JSON-LD
+work.
+This
+section
+expands
+on
+the
+basic
+principles
+of
+the
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>
+and
+demonstrates
+how
+more
+advanced
+use
+cases
+can
+be
+achieved
+using
+JSON-LD.
+</p>
+<p>
+In
+general,
+contexts
+may
+be
+used
+at
+any
+time
+a
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+is
+defined.
+The
+only
+time
+that
+one
+cannot
+express
+a
+context
+is
+inside
+a
+context
+definition
+itself.
+For
+example,
+a
+<a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">
+JSON-LD
+document
+</a>
+may
+use
+more
+than
+one
+context
+at
+different
+points
+in
+a
+document:
+</p>
+<del class="diff-old"> [
+ {
+
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/",
+ "depiction": "http://twitter.com/account/profile_image/manusporny"
+ },
+ {
+
+ "name": "The Empire State Building",
+ "description": "The Empire State Building is a 102-story landmark in New York City.",
+ "geo": {
+ "latitude": "40.75",
+ "longitude": "73.98"
+ }
+ }
+</del>
+ <div class="example"><div class="example-title"><span>Example 23</span>: Using multiple contexts</div><pre class="example">[
+<ins class="diff-chg"> {
+</ins> <span class="diff">"@context": "http://example.org/contexts/person.jsonld",</span>
+<ins class="diff-chg">
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/",
+ "depiction": "http://twitter.com/account/profile_image/manusporny"
+ },
+ {
+</ins> <span class="diff">"@context": "http://example.org/contexts/place.jsonld",</span>
+<ins class="diff-chg">
+ "name": "The Empire State Building",
+ "description": "The Empire State Building is a 102-story landmark in New York City.",
+ "geo": {
+ "latitude": "40.75",
+ "longitude": "73.98"
+ }
+ }
+</ins>
+]
+</pre>
+</div>
+<p>
+Duplicate
+context
+<a href="#dfn-term" title="term" class="tref internalDFN">
+terms
+</a>
+are
+overridden
+using
+a
+last-defined-wins
+mechanism.
+</p>
+<del class="diff-old"> {
+ "@context":
+ {
+ "name": "http://example.com/person#name",
+ "details": "http://example.com/person#details"
+ },
+ "": "Markus Lanthaler",
+ ...
+ "details":
+ {
+ "@context": {
+ "name": "http://example.com/organization#name"
+ },
+ "": "Graz University of Technology"
+ }
+</del>
+ <div class="example"><div class="example-title"><span>Example 24</span>: Scoped contexts within node objects</div><pre class="example">{
+ <span class="diff">"@context":
+<ins class="diff-chg"> {
+ "name": "http://example.com/person#name",
+ "details": "http://example.com/person#details"
+ },</span>
+ "<span class="diff">name</span>": "Markus Lanthaler",
+ ...
+ "details":
+ {
+</ins> <span class="diff">"@context": {
+<ins class="diff-chg">
+ "name": "http://example.com/organization#name"
+ },</span>
+ "<span class="diff">name</span>": "Graz University of Technology"
+ }
+</ins>
+}
+</pre>
+</div>
+<p>
+In
+the
+example
+above,
+the
+<code>
+name
+</code>
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+is
+overridden
+in
+the
+more
+deeply
+nested
+<code>
+details
+</code>
+structure.
+Note
+that
+this
+is
+rarely
+a
+good
+authoring
+practice
+and
+is
+typically
+used
+when
+working
+with
+legacy
+applications
+that
+depend
+on
+a
+specific
+structure
+of
+the
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>.
+If
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+is
+redefined
+within
+a
+context,
+all
+previous
+rules
+associated
+with
+the
+previous
+definition
+are
+removed.
+If
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+is
+redefined
+to
+<code>
+null
+</code>,
+the
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+is
+effectively
+removed
+from
+the
+list
+of
+<a href="#dfn-term" title="term" class="tref internalDFN">
+terms
+</a>
+defined
+in
+the
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>.
+</p>
+<p>
+Multiple
+contexts
+may
+be
+combined
+using
+an
+<a href="#dfn-array" title="array" class="tref internalDFN">
+array
+</a>,
+which
+is
+processed
+in
+order.
+The
+set
+of
+contexts
+defined
+within
+a
+specific
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+are
+referred
+to
+as
+<dfn id="dfn-local-context" title="local-context">
+local
+contexts
+</dfn>.
+The
+<dfn id="dfn-active-context" title="active-context">
+active
+context
+</dfn>
+refers
+to
+the
+accumulation
+of
+<a href="#dfn-local-context" title="local-context" class="tref internalDFN">
+local
+contexts
+</a>
+that
+are
+in
+scope
+at
+a
+specific
+point
+within
+the
+document.
+Setting
+a
+<a href="#dfn-local-context" title="local-context" class="tref internalDFN">
+local
+context
+</a>
+to
+<code>
+null
+</code>
+effectively
+resets
+the
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>
+to
+an
+empty
+context.
+The
+following
+example
+specifies
+an
+external
+context
+and
+then
+layers
+an
+embedded
+context
+on
+top
+of
+the
+external
+context:
+</p>
+<del class="diff-old"> {
+ "@context": [
+ "http://json-ld.org/contexts/person.jsonld",
+ {
+ "pic": "http://xmlns.com/foaf/0.1/depiction"
+ }
+ ],
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/",
+
+</del>
+ <div class="example"><div class="example-title"><span>Example 25</span>: Combining external and local contexts</div><pre class="example">{
+ <span class="diff">"@context": [
+<ins class="diff-chg"> "http://json-ld.org/contexts/person.jsonld",
+ {
+ "pic": "http://xmlns.com/foaf/0.1/depiction"
+ }
+ ],</span>
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/",
+</ins> <span class="diff">"pic": "http://twitter.com/account/profile_image/manusporny"</span>
+}
+</pre>
+</div>
+<div class="note">
+<div class="note-title">
+<span>
+Note
+</span>
+</div>
+<p class="">
+It
+is
+a
+best
+practice
+to
+put
+the
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>
+definition
+at
+the
+top
+of
+the
+JSON-LD
+document.
+</p>
+</div>
+<div class="note">
+<div class="note-title">
+<span>
+Note
+</span>
+</div>
+<p class="">
+<del class="diff-old">While
+it
+is
+possible
+to
+define
+a
+compact
+IRI
+,
+or
+an
+absolute
+IRI
+to
+expand
+to
+some
+other
+unrelated
+IRI
+(for
+example,
+foaf:name
+expanding
+to
+http://example.org/unrelated#species
+),
+such
+usage
+is
+strongly
+discouraged.
+Note
+</del>
+To
+avoid
+forward-compatibility
+issues,
+<a href="#dfn-term" title="term" class="tref internalDFN">
+terms
+</a>
+starting
+with
+an
+<code>
+@
+</code>
+character
+are
+to
+be
+avoided
+as
+they
+might
+be
+used
+as
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keywords
+</a>
+in
+future
+versions
+of
+JSON-LD.
+Furthermore,
+the
+use
+of
+empty
+<a href="#dfn-term" title="term" class="tref internalDFN">
+terms
+</a>
+(
+<code>
+""
+</code>
+)
+is
+discouraged
+as
+not
+all
+programming
+languages
+are
+able
+to
+handle
+empty
+property
+names.
+</p>
+</div>
+</section>
+<section id="interpreting-json-as-json-ld">
+<h3>
+<span class="secno">
+<del class="diff-old">6.4.1
+</del>
+<ins class="diff-chg">6.5
+</ins>
+</span>
+Interpreting
+JSON
+as
+JSON-LD
+</h3>
+<p>
+Ordinary
+JSON
+documents
+can
+be
+interpreted
+as
+JSON-LD
+by
+referencing
+a
+JSON-LD
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>
+document
+in
+an
+HTTP
+Link
+Header.
+Doing
+so
+allows
+JSON
+to
+be
+unambiguously
+machine-readable
+without
+requiring
+developers
+to
+drastically
+change
+their
+markup
+and
+provides
+an
+upgrade
+path
+for
+existing
+infrastructure
+without
+breaking
+existing
+clients
+that
+rely
+on
+the
+<code>
+application/json
+</code>
+media
+type.
+</p>
+<p>
+In
+order
+to
+use
+an
+external
+context
+with
+an
+ordinary
+JSON
+document,
+an
+author
+<em title="must" class="rfc2119">
+must
+</em>
+specify
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+to
+a
+valid
+<a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">
+JSON-LD
+document
+</a>
+in
+an
+HTTP
+Link
+Header
+[
+<cite>
+<a href="#bib-RFC5988" class="bibref">
+RFC5988
+</a>
+</cite>
+]
+using
+the
+<code>
+http://www.w3.org/ns/json-ld#context
+</code>
+link
+relation.
+The
+referenced
+document
+<em title="must" class="rfc2119">
+must
+</em>
+have
+a
+top-level
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>.
+The
+<code>
+@context
+</code>
+subtree
+within
+that
+object
+is
+added
+to
+the
+top-level
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+of
+the
+referencing
+document.
+If
+an
+<a href="#dfn-array" title="array" class="tref internalDFN">
+array
+</a>
+is
+at
+the
+top-level
+of
+the
+referencing
+document
+and
+its
+items
+are
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+objects
+</a>,
+the
+<code>
+@context
+</code>
+subtree
+is
+added
+to
+all
+<a href="#dfn-array" title="array" class="tref internalDFN">
+array
+</a>
+items.
+All
+extra
+information
+located
+outside
+of
+the
+<code>
+@context
+</code>
+subtree
+in
+the
+referenced
+document
+<em title="must" class="rfc2119">
+must
+</em>
+be
+discarded.
+Effectively
+this
+means
+that
+the
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>
+is
+initialized
+with
+the
+referenced
+external
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>.
+</p>
+<p>
+The
+following
+example
+demonstrates
+the
+use
+of
+an
+external
+context
+with
+an
+ordinary
+JSON
+document:
+</p>
+<del class="diff-old"> GET /ordinary-json-document.json HTTP/1.1
+Host: example.com
+Accept: application/ld+json,application/json,*/*;q=0.1
+====================================
+HTTP/1.0 200 OK
+...
+Content-Type:
+{
+ "name": "Markus Lanthaler",
+ "homepage": "http://www.markus-lanthaler.com/",
+ "image": "http://twitter.com/account/profile_image/markuslanthaler"
+</del>
+ <div class="example"><div class="example-title"><span>Example 26</span>: Referencing a JSON-LD context from a JSON document via an HTTP Link Header</div><pre class="example">GET /ordinary-json-document.json HTTP/1.1
+<ins class="diff-chg">Host: example.com
+Accept: application/ld+json,application/json,*/*;q=0.1
+
+====================================
+
+HTTP/1.0 200 OK
+...
+Content-Type: <span class="diff">application/json</span>
+</ins><span class="diff">Link: <http://json-ld.org/contexts/person.jsonld>; rel="http://www.w3.org/ns/json-ld#context"; type="application/ld+json"</span>
+<ins class="diff-chg">
+
+{
+ "name": "Markus Lanthaler",
+ "homepage": "http://www.markus-lanthaler.com/",
+ "image": "http://twitter.com/account/profile_image/markuslanthaler"
+</ins>
+}
+</pre>
+</div>
+<p>
+Please
+note
+that
+<a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">
+JSON-LD
+documents
+</a>
+served
+with
+the
+<code>
+application/ld+json
+</code>
+media
+type
+<em title="must" class="rfc2119">
+must
+</em>
+have
+all
+context
+information,
+including
+references
+to
+external
+contexts,
+within
+the
+body
+of
+the
+document.
+Contexts
+linked
+via
+a
+<code>
+http://www.w3.org/ns/json-ld#context
+</code>
+HTTP
+Link
+Header
+<em title="must" class="rfc2119">
+must
+</em>
+be
+ignored
+for
+such
+documents.
+</p>
+</section>
+<section id="string-internationalization">
+<h3>
+<span class="secno">
+<del class="diff-old">6.5
+</del>
+<ins class="diff-chg">6.6
+</ins>
+</span>
+String
+Internationalization
+</h3>
+<p>
+At
+times,
+it
+is
+important
+to
+annotate
+a
+<a href="#dfn-string" title="string" class="tref internalDFN">
+string
+</a>
+with
+its
+language.
+In
+JSON-LD
+this
+is
+possible
+in
+a
+variety
+of
+ways.
+First,
+it
+is
+possible
+to
+define
+a
+default
+language
+for
+a
+JSON-LD
+document
+by
+setting
+the
+<code>
+@language
+</code>
+key
+in
+the
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>:
+</p>
+<del class="diff-old"> {
+ "@context":
+ {
+ ...
+ "@language": "ja"
+ },
+ "name": ,
+ "occupation":
+</del>
+ <div class="example"><div class="example-title"><span>Example 27</span>: Setting the default language of a JSON-LD document</div><pre class="example">{
+ <span class="diff">"@context":
+<ins class="diff-chg"> {
+ ...
+ "@language": "ja"
+ }</span>,
+ "name": <span class="diff">"花澄"</span>,
+ "occupation": <span class="diff">"科学者"</span>
+</ins>
+}
+</pre>
+</div>
+<p>
+The
+example
+above
+would
+associate
+the
+<code>
+ja
+</code>
+language
+code
+with
+the
+two
+<a href="#dfn-string" title="string" class="tref internalDFN">
+strings
+</a>
+<em>
+花澄
+</em>
+and
+<em>
+科学者
+</em>.
+Languages
+codes
+are
+defined
+in
+[
+<cite>
+<a href="#bib-BCP47" class="bibref">
+BCP47
+</a>
+</cite>
+].
+</p>
+<p>
+To
+clear
+the
+default
+language
+for
+a
+subtree,
+<code>
+@language
+</code>
+can
+be
+set
+to
+<code>
+null
+</code>
+in
+a
+<a href="#dfn-local-context" title="local-context" class="tref internalDFN">
+local
+context
+</a>
+as
+follows:
+</p>
+<del class="diff-old"> {
+ "@context": {
+ ...
+ "@language": "ja"
+ },
+ "name": "花澄",
+ "details": {
+ "@context": {
+ "@language": null
+ },
+ "occupation": "Ninja"
+ }
+</del>
+ <div class="example"><div class="example-title"><span>Example 28</span>: Clearing default language</div><pre class="example">{
+<ins class="diff-chg"> "@context": {
+ ...
+ "@language": "ja"
+ },
+ "name": "花澄",
+ "details": {
+</ins><span class="diff"> "@context": {
+<ins class="diff-chg">
+ "@language": null
+ }</span>,
+ "occupation": "Ninja"
+ }
+</ins>
+}
+</pre>
+</div>
+<p>
+Second,
+it
+is
+possible
+to
+associate
+a
+language
+with
+a
+specific
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+using
+an
+<a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">
+expanded
+term
+definition
+</a>:
+</p>
+<del class="diff-old"> {
+ "@context": {
+ ...
+ "ex": "http://example.com/vocab/",
+ "@language": "ja",
+ "name": { "@id": "ex:name", },
+ "occupation": { "@id": "ex:occupation" },
+ "occupation_en": { "@id": "ex:occupation", },
+ "occupation_cs": { "@id": "ex:occupation", }
+ },
+ "name": "Yagyū Muneyoshi",
+ "occupation": "忍者",
+ "occupation_en": "Ninja",
+ "occupation_cs": "Nindža",
+ ...
+</del>
+ <div class="example"><div class="example-title"><span>Example 29</span>: Expanded term definition with language</div><pre class="example">{
+<ins class="diff-chg"> "@context": {
+ ...
+ "ex": "http://example.com/vocab/",
+ "@language": "ja",
+ "name": { "@id": "ex:name", <span class="diff">"@language": null</span> },
+ "occupation": { "@id": "ex:occupation" },
+ "occupation_en": { "@id": "ex:occupation", <span class="diff">"@language": "en"</span> },
+ "occupation_cs": { "@id": "ex:occupation", <span class="diff">"@language": "cs"</span> }
+ },
+</ins> <span class="diff">"name": "Yagyū Muneyoshi",
+<ins class="diff-chg">
+ "occupation": "忍者",
+ "occupation_en": "Ninja",
+ "occupation_cs": "Nindža",</span>
+ ...
+</ins>
+}
+</pre>
+</div>
+<p>
+The
+example
+above
+would
+associate
+<em>
+忍者
+</em>
+with
+the
+specified
+default
+language
+code
+<code>
+ja
+</code>,
+<em>
+Ninja
+</em>
+with
+the
+language
+code
+<code>
+en
+</code>,
+and
+<em>
+Nindža
+</em>
+with
+the
+language
+code
+<code>
+cs
+</code>.
+The
+value
+of
+<code>
+name
+</code>,
+<em>
+Yagyū
+Muneyoshi
+</em>
+wouldn't
+be
+associated
+with
+any
+language
+code
+since
+<code>
+@language
+</code>
+was
+reset
+to
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>
+in
+the
+<a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">
+expanded
+term
+definition
+</a>.
+</p>
+<div class="note">
+<div class="note-title">
+<span>
+Note
+</span>
+</div>
+<p class="">
+Language
+associations
+can
+only
+be
+applied
+to
+plain
+literal
+<a href="#dfn-string" title="string" class="tref internalDFN">
+strings
+</a>.
+<a href="#dfn-typed-value" title="typed-value" class="tref internalDFN">
+Typed
+values
+</a>
+or
+values
+that
+are
+subject
+to
+<a class="sec-ref" href="#type-coercion">
+<span class="secno">
+6.3
+</span>
+<span class="sec-title">
+Type
+Coercion
+</span>
+</a>
+cannot
+be
+language
+tagged.
+</p>
+</div>
+<p>
+Just
+as
+in
+the
+example
+above,
+systems
+often
+need
+to
+express
+the
+value
+of
+a
+property
+in
+multiple
+languages.
+Typically,
+such
+systems
+also
+try
+to
+ensure
+that
+developers
+have
+a
+programmatically
+easy
+way
+to
+navigate
+the
+data
+structures
+for
+the
+language-specific
+data.
+In
+this
+case,
+<a href="#dfn-language-map" title="language-map" class="tref internalDFN">
+language
+maps
+</a>
+may
+be
+utilized.
+</p>
+<del class="diff-old"> {
+ "@context":
+ {
+ ...
+ "occupation": { "@id": "ex:occupation", }
+ },
+ "name": "Yagyū Muneyoshi",
+ "occupation":
+ {
+ "ja": "忍者",
+ "en": "Ninja",
+ "cs": "Nindža"
+ }
+ ...
+</del>
+ <div class="example"><div class="example-title"><span>Example 30</span>: Language map expressing a property in three languages</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+ ...
+ "occupation": { "@id": "ex:occupation", <span class="diff">"@container": "@language"</span> }
+ },
+ "name": "Yagyū Muneyoshi",
+ "occupation":
+</ins> <span class="diff">{
+<ins class="diff-chg">
+ "ja": "忍者",
+ "en": "Ninja",
+ "cs": "Nindža"
+ }</span>
+ ...
+</ins>
+}
+</pre>
+</div>
+<p>
+The
+example
+above
+expresses
+exactly
+the
+same
+information
+as
+the
+previous
+example
+but
+consolidates
+all
+values
+in
+a
+single
+property.
+To
+access
+the
+value
+in
+a
+specific
+language
+in
+a
+programming
+language
+supporting
+dot-notation
+accessors
+for
+object
+properties,
+a
+developer
+may
+use
+the
+<code>
+property.language
+</code>
+pattern.
+For
+example,
+to
+access
+the
+occupation
+in
+English,
+a
+developer
+would
+use
+the
+following
+code
+snippet:
+<code>
+obj.occupation.en
+</code>.
+</p>
+<p>
+Third,
+it
+is
+possible
+to
+override
+the
+default
+language
+by
+using
+an
+<a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">
+expanded
+value
+</a>:
+</p>
+<del class="diff-old"> {
+ "@context": {
+ ...
+ "@language": "ja"
+ },
+ "name": "花澄",
+ "occupation": {
+ "@value": "Scientist",
+ "@language": "en"
+ }
+</del>
+ <div class="example"><div class="example-title"><span>Example 31</span>: Overriding default language using an expanded value</div><pre class="example">{
+<ins class="diff-chg"> "@context": {
+ ...
+ "@language": "ja"
+ },
+ "name": "花澄",
+ "occupation": <span class="diff">{
+ "@value": "Scientist",
+ "@language": "en"
+ }</span>
+</ins>
+}
+</pre>
+</div>
+<p>
+This
+makes
+it
+possible
+to
+specify
+a
+plain
+string
+by
+omitting
+the
+<code>
+@language
+</code>
+tag
+or
+setting
+it
+to
+<code>
+null
+</code>
+when
+expressing
+it
+using
+an
+<a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">
+expanded
+value
+</a>:
+</p>
+<del class="diff-old"> {
+ "@context": {
+ ...
+ "@language": "ja"
+ },
+ "name": {
+ "@value": "Frank"
+ },
+ "occupation": {
+ "@value": "Ninja",
+ "@language": "en"
+ },
+ "speciality": "手裏剣"
+</del>
+ <div class="example"><div class="example-title"><span>Example 32</span>: Removing language information using an expanded value</div><pre class="example">{
+<ins class="diff-chg"> "@context": {
+ ...
+ "@language": "ja"
+ },
+ "name": <span class="diff">{
+ "@value": "Frank"
+ }</span>,
+ "occupation": {
+ "@value": "Ninja",
+ "@language": "en"
+ },
+ "speciality": "手裏剣"
+</ins>
+}
+</pre>
+</div>
+</section>
+<section id="overriding-vocab">
+<h3>
+<span class="secno">
+<del class="diff-old">6.6
+</del>
+<ins class="diff-chg">6.7
+</ins>
+</span>
+Overriding
+@vocab
+</h3>
+<p>
+If
+<code>
+@vocab
+</code>
+is
+used
+but
+certain
+keys
+in
+an
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+object
+</a>
+should
+not
+be
+expanded
+using
+the
+vocabulary
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+can
+be
+explicitly
+set
+to
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>
+in
+the
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>.
+For
+instance,
+in
+the
+example
+below
+the
+<code>
+databaseId
+</code>
+member
+would
+be
+ignored
+by
+a
+JSON-LD
+processor.
+</p>
+<p>
+</p>
+<del class="diff-old"> {
+ "@context":
+ {
+ "@vocab": "http://schema.org/",
+
+ },
+ "name": "Gregg Kellogg",
+
+</del>
+ <div class="example"><div class="example-title"><span>Example 33</span>: Using the null keyword to ignore data</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+ "@vocab": "http://schema.org/",
+</ins> <span class="diff">"databaseId": null</span>
+<ins class="diff-chg">
+ },
+ "name": "Gregg Kellogg",
+</ins> <span class="diff">"databaseId": "23987520"</span>
+}
+</pre>
+</div>
+</section>
+<section id="property-generators">
+<h3>
+<span class="secno">
+<del class="diff-old">6.7
+</del>
+<ins class="diff-chg">6.8
+</ins>
+</span>
+Property
+Generators
+</h3>
+<p>
+At
+times,
+an
+author
+may
+find
+that
+they
+need
+to
+express
+the
+same
+value
+for
+multiple
+properties.
+The
+simplest
+approach
+to
+accomplish
+this
+goal
+would
+be
+to
+do
+the
+following:
+</p>
+<del class="diff-old">{
+ "@context":
+ {
+ ,
+ ,
+
+ },
+ "@id": "http://example.com/book",
+ ,
+ ,
+
+</del>
+<div class="example"><div class="example-title"><span>Example 34</span>: Verbose expression of multiple properties with the same value</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+</ins> <span class="diff">"title1": "http://purl.org/dc/terms/title"</span>,
+ <span class="diff">"title2": "http://schema.org/name"</span>,
+ <span class="diff">"title3": "http://www.w3.org/2000/01/rdf-schema#label"</span>
+<ins class="diff-chg">
+ },
+ "@id": "http://example.com/book",
+</ins> <span class="diff">"title1": "The Count of Monte Cristo"</span>,
+ <span class="diff">"title2": "The Count of Monte Cristo"</span>,
+ <span class="diff">"title3": "The Count of Monte Cristo"</span>
+}
+</pre>
+</div>
+<p>
+Unfortunately,
+the
+approach
+above
+produces
+redundant
+data
+and
+would
+become
+a
+publishing
+burden
+for
+large
+data
+sets.
+In
+these
+situations,
+the
+author
+may
+use
+a
+<dfn id="dfn-property-generator" title="property-generator">
+property
+generator
+</dfn>
+to
+express
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+that
+maps
+to
+multiple
+<a href="#dfn-property" title="property" class="tref internalDFN">
+properties
+</a>
+in
+the
+<a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">
+JSON-LD
+graph
+</a>.
+This
+method
+can
+be
+accomplished
+by
+using
+the
+following
+markup
+pattern:
+</p>
+<del class="diff-old">{
+ "@context":
+ {
+ "title": { "@id": [ "http://purl.org/dc/terms/title",
+ "http://schema.org/name",
+ "http://www.w3.org/2000/01/rdf-schema#label" ] }
+ },
+ "@id": "http://example.com/book",
+
+</del>
+<div class="example"><div class="example-title"><span>Example 35</span>: Generating multiple properties using a single term</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+</ins> <span class="diff">"title": { "@id": [ "http://purl.org/dc/terms/title",
+<ins class="diff-chg">
+ "http://schema.org/name",
+ "http://www.w3.org/2000/01/rdf-schema#label" ] }</span>
+ },
+ "@id": "http://example.com/book",
+</ins> <span class="diff">"title": "The Count of Monte Cristo"</span>
+}
+</pre>
+</div>
+<p>
+While
+the
+term
+above
+is
+only
+used
+once
+outside
+of
+the
+<code>
+@context
+</code>,
+the
+document
+above
+will
+be
+interpreted
+like
+so:
+</p>
+<table class="example">
+<thead>
+<tr>
+<th>
+Subject
+</th>
+<th>
+Property
+</th>
+<th>
+Value
+</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>
+http://example.com/book
+</td>
+<td>
+http://purl.org/dc/terms/title
+</td>
+<td>
+The
+Count
+of
+Monte
+Cristo
+</td>
+</tr>
+<tr>
+<td>
+http://example.com/book
+</td>
+<td>
+http://schema.org/name
+</td>
+<td>
+The
+Count
+of
+Monte
+Cristo
+</td>
+</tr>
+<tr>
+<td>
+http://example.com/book
+</td>
+<td>
+http://www.w3.org/2000/01/rdf-schema#label
+</td>
+<td>
+The
+Count
+of
+Monte
+Cristo
+</td>
+</tr>
+</tbody>
+</table>
+</section>
+<section id="iri-expansion-within-a-context">
+<h3>
+<span class="secno">
+<del class="diff-old">6.8
+</del>
+<ins class="diff-chg">6.9
+</ins>
+</span>
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+Expansion
+Within
+a
+Context
+</h3>
+<p>
+In
+general,
+normal
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+expansion
+rules
+apply
+anywhere
+an
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+is
+expected
+(see
+<a class="sec-ref" href="#iris">
+<span class="secno">
+5.2
+</span>
+<span class="sec-title">
+IRIs
+</span>
+</a>
+).
+Within
+a
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>
+definition,
+this
+can
+mean
+that
+terms
+defined
+within
+the
+context
+may
+also
+be
+used
+within
+that
+context
+as
+long
+as
+there
+are
+no
+circular
+dependencies.
+For
+example,
+it
+is
+common
+to
+use
+the
+<code>
+xsd
+</code>
+namespace
+when
+defining
+<a href="#dfn-typed-value" title="typed-value" class="tref internalDFN">
+typed
+value
+</a>
+s:
+</p>
+<del class="diff-old">{
+ "@context":
+ {
+ ,
+ "name": "http://xmlns.com/foaf/0.1/name",
+ "age":
+ {
+ "@id": "http://xmlns.com/foaf/0.1/age",
+ "@type":
+ },
+ "homepage":
+ {
+ "@id": "http://xmlns.com/foaf/0.1/homepage",
+ "@type": "@id"
+ }
+ },
+ ...
+</del>
+<div class="example"><div class="example-title"><span>Example 36</span>: IRI expansion within a context</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+</ins> <span class="diff">"xsd": "http://www.w3.org/2001/XMLSchema#"</span>,
+<ins class="diff-chg">
+ "name": "http://xmlns.com/foaf/0.1/name",
+ "age":
+ {
+ "@id": "http://xmlns.com/foaf/0.1/age",
+ "@type": <span class="diff">"xsd:integer"</span>
+ },
+ "homepage":
+ {
+ "@id": "http://xmlns.com/foaf/0.1/homepage",
+ "@type": "@id"
+ }
+ },
+ ...
+</ins>
+}
+</pre>
+</div>
+<p>
+In
+this
+example,
+the
+<code>
+xsd
+</code>
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+is
+defined
+and
+used
+as
+a
+<a href="#dfn-prefix" title="prefix" class="tref internalDFN">
+prefix
+</a>
+for
+the
+<code>
+@type
+</code>
+coercion
+of
+the
+<code>
+age
+</code>
+property.
+</p>
+<p>
+<a href="#dfn-term" title="term" class="tref internalDFN">
+Terms
+</a>
+may
+also
+be
+used
+when
+defining
+the
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+of
+another
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>:
+</p>
+<del class="diff-old">{
+ "@context":
+ {
+ ,
+ "xsd": "http://www.w3.org/2001/XMLSchema#",
+ "name": ,
+ "age":
+ {
+ "@id": ,
+ "@type": "xsd:integer"
+ },
+ "homepage":
+ {
+ "@id": ,
+ "@type": "@id"
+ }
+ },
+ ...
+</del>
+<div class="example"><div class="example-title"><span>Example 37</span>: Using a term to define the IRI of another term within a context</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+</ins> <span class="diff">"foaf": "http://xmlns.com/foaf/0.1/"</span>,
+<ins class="diff-chg">
+ "xsd": "http://www.w3.org/2001/XMLSchema#",
+ "name": <span class="diff">"foaf:name"</span>,
+ "age":
+ {
+ "@id": <span class="diff">"foaf:age"</span>,
+ "@type": "xsd:integer"
+ },
+ "homepage":
+ {
+ "@id": <span class="diff">"foaf:homepage"</span>,
+ "@type": "@id"
+ }
+ },
+ ...
+</ins>
+}
+</pre>
+</div>
+<p>
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+Compact
+IRIs
+</a>
+and
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>
+may
+be
+used
+on
+the
+left-hand
+side
+of
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+definition.
+</p>
+<del class="diff-old">{
+ "@context":
+ {
+ ,
+ "xsd": "http://www.w3.org/2001/XMLSchema#",
+ "name": "foaf:name",
+ "":
+ {
+ "@type": "xsd:integer"
+ },
+ "":
+ {
+ "@type": "@id"
+ }
+ },
+ ...
+</del>
+<div class="example"><div class="example-title"><span>Example 38</span>: Using a compact IRI as a term</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+</ins> <span class="diff">"foaf": "http://xmlns.com/foaf/0.1/"</span>,
+<ins class="diff-chg">
+ "xsd": "http://www.w3.org/2001/XMLSchema#",
+ "name": "foaf:name",
+ "<span class="diff">foaf:age</span>":
+ {
+ "@type": "xsd:integer"
+ },
+ "<span class="diff">foaf:homepage</span>":
+</ins> <span class="diff">{
+<ins class="diff-chg">
+ "@type": "@id"
+ }</span>
+ },
+ ...
+</ins>
+}
+</pre>
+</div>
+<p>
+In
+this
+example,
+the
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+form
+is
+used
+in
+two
+different
+ways.
+In
+the
+first
+approach,
+<code>
+foaf:age
+</code>
+declares
+both
+the
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+for
+the
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+(using
+short-form)
+as
+well
+as
+the
+<code>
+@type
+</code>
+associated
+with
+the
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>.
+In
+the
+second
+approach,
+only
+the
+<code>
+@type
+</code>
+associated
+with
+the
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+is
+specified.
+The
+full
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+for
+<code>
+foaf:homepage
+</code>
+is
+determined
+by
+looking
+up
+the
+<code>
+foaf
+</code>
+<a href="#dfn-prefix" title="prefix" class="tref internalDFN">
+prefix
+</a>
+in
+the
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>.
+</p>
+<p>
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+Absolute
+IRIs
+</a>
+may
+also
+be
+used
+in
+the
+key
+position
+in
+a
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>:
+</p>
+<del class="diff-old">{
+ "@context":
+ {
+ "foaf": "http://xmlns.com/foaf/0.1/",
+ "xsd": "http://www.w3.org/2001/XMLSchema#",
+ "name": "foaf:name",
+ "foaf:age":
+ {
+ "@id": "foaf:age",
+ "@type": "xsd:integer"
+ },
+ "":
+ {
+ "@type": "@id"
+ }
+ },
+ ...
+</del>
+<div class="example"><div class="example-title"><span>Example 39</span>: Associating context definitions with absolute IRIs</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+ "foaf": "http://xmlns.com/foaf/0.1/",
+ "xsd": "http://www.w3.org/2001/XMLSchema#",
+ "name": "foaf:name",
+ "foaf:age":
+ {
+ "@id": "foaf:age",
+ "@type": "xsd:integer"
+ },
+ "<span class="diff">http://xmlns.com/foaf/0.1/homepage</span>":
+ {
+ "@type": "@id"
+ }
+ },
+ ...
+</ins>
+}
+</pre>
+</div>
+<p>
+In
+order
+for
+the
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+to
+match
+above,
+the
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+needs
+to
+be
+used
+in
+the
+<a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">
+JSON-LD
+document
+</a>.
+Also
+note
+that
+<code>
+foaf:homepage
+</code>
+will
+not
+use
+the
+<code>
+{
+"@type":
+"@id"
+}
+</code>
+declaration
+because
+<code>
+foaf:homepage
+</code>
+is
+not
+the
+same
+as
+<code>
+http://xmlns.com/foaf/0.1/homepage
+</code>.
+That
+is,
+<a href="#dfn-term" title="term" class="tref internalDFN">
+terms
+</a>
+are
+looked
+up
+in
+a
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>
+using
+direct
+string
+comparison
+before
+the
+<a href="#dfn-prefix" title="prefix" class="tref internalDFN">
+prefix
+</a>
+lookup
+mechanism
+is
+applied.
+</p>
+<div class="note">
+<div class="note-title">
+<span>
+<ins class="diff-new">Note
+</ins></span></div><p class=""><ins class="diff-new">
+While
+it
+is
+possible
+to
+define
+a
+</ins><a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN"><ins class="diff-new">
+compact
+</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
+IRI
+</ins></abbr></a>,<ins class="diff-new">
+or
+an
+</ins><a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN"><ins class="diff-new">
+absolute
+</ins><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
+IRI
+</ins></abbr></a><ins class="diff-new">
+to
+expand
+to
+some
+other
+unrelated
+</ins><a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
+IRI
+</ins></abbr></a><ins class="diff-new">
+(for
+example,
+</ins><code><ins class="diff-new">
+foaf:name
+</ins></code><ins class="diff-new">
+expanding
+to
+</ins><code><ins class="diff-new">
+http://example.org/unrelated#species
+</ins></code><ins class="diff-new">
+),
+such
+usage
+is
+strongly
+discouraged.
+</ins></p></div>
+<p>
+The
+only
+exception
+for
+using
+terms
+in
+the
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>
+is
+that
+circular
+definitions
+are
+not
+allowed.
+That
+is,
+a
+definition
+of
+<em>
+term1
+</em>
+cannot
+depend
+on
+the
+definition
+of
+<em>
+term2
+</em>
+if
+<em>
+term2
+</em>
+also
+depends
+on
+<em>
+term1
+</em>.
+For
+example,
+the
+following
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>
+definition
+is
+illegal:
+</p>
+<del class="diff-old">{
+ "@context":
+ {
+ "term1": "term2:foo",
+ "term2": "term1:bar"
+ },
+ ...
+</del>
+<div class="example"><div class="example-title"><span>Example 40</span>: Illegal circular definition of terms within a context</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+</ins> <span class="diff">"term1": "term2:foo",
+<ins class="diff-chg">
+ "term2": "term1:bar"</span>
+ },
+ ...
+</ins>
+}
+</pre>
+</div>
+</section>
+<section id="sets-and-lists">
+<h3>
+<span class="secno">
+<del class="diff-old">6.9
+</del>
+<ins class="diff-chg">6.10
+</ins>
+</span>
+Sets
+and
+Lists
+</h3>
+<p>
+A
+JSON-LD
+author
+can
+express
+multiple
+values
+in
+a
+compact
+way
+by
+using
+<a href="#dfn-array" title="array" class="tref internalDFN">
+arrays
+</a>.
+Since
+graphs
+do
+not
+describe
+ordering
+for
+links
+between
+nodes,
+arrays
+in
+JSON-LD
+do
+not
+provide
+an
+ordering
+of
+the
+contained
+elements
+by
+default.
+This
+is
+exactly
+the
+opposite
+from
+regular
+JSON
+arrays,
+which
+are
+ordered
+by
+default.
+For
+example,
+consider
+the
+following
+simple
+document:
+</p>
+<del class="diff-old">{
+...
+ "@id": "http://example.org/people#joebob",
+ "nick": ,
+...
+</del>
+<div class="example"><div class="example-title"><span>Example 41</span>: Multiple values with no inherent order</div><pre class="example">{
+<ins class="diff-chg">...
+ "@id": "http://example.org/people#joebob",
+ "nick": <span class="diff">[ "joe", "bob", "JB" ]</span>,
+...
+</ins>
+}
+</pre>
+</div>
+<p>
+The
+markup
+shown
+above
+would
+result
+in
+the
+following
+data
+being
+generated,
+each
+relating
+the
+node
+to
+an
+individual
+value,
+with
+no
+inherent
+order:
+</p>
+<table class="example">
+<thead>
+<tr>
+<th>
+Subject
+</th>
+<th>
+Property
+</th>
+<th>
+Value
+</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>
+http://example.org/people#joebob
+</td>
+<td>
+http://xmlns.com/foaf/0.1/nick
+</td>
+<td>
+joe
+</td>
+</tr>
+<tr>
+<td>
+http://example.org/people#joebob
+</td>
+<td>
+http://xmlns.com/foaf/0.1/nick
+</td>
+<td>
+bob
+</td>
+</tr>
+<tr>
+<td>
+http://example.org/people#joebob
+</td>
+<td>
+http://xmlns.com/foaf/0.1/nick
+</td>
+<td>
+JB
+</td>
+</tr>
+</tbody>
+</table>
+<p>
+Multiple
+values
+may
+also
+be
+expressed
+using
+the
+expanded
+form:
+</p>
+<del class="diff-old">{
+ "@id": "http://example.org/articles/8",
+ "dc:title":
+ [
+ {
+ "@value": "Das Kapital",
+ "@language": "de"
+ },
+ {
+ "@value": "Capital",
+ "@language": "en"
+ }
+ ]
+</del>
+<div class="example"><div class="example-title"><span>Example 42</span>: Using an expanded form to set multiple values</div><pre class="example">{
+<ins class="diff-chg"> "@id": "http://example.org/articles/8",
+ "dc:title": <span class="diff">
+ [
+ {
+ "@value": "Das Kapital",
+ "@language": "de"
+ },
+ {
+ "@value": "Capital",
+ "@language": "en"
+ }
+ ]</span>
+</ins>
+}
+</pre>
+</div>
+<p>
+The
+markup
+shown
+above
+would
+generate
+the
+following
+data,
+again
+with
+no
+inherent
+order:
+</p>
+<table class="example">
+<thead>
+<tr>
+<th>
+Subject
+</th>
+<th>
+Property
+</th>
+<th>
+Value
+</th>
+<th>
+Language
+</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>
+http://example.org/articles/8
+</td>
+<td>
+http://purl.org/dc/terms/title
+</td>
+<td>
+Das
+Kapital
+</td>
+<td>
+de
+</td>
+</tr>
+<tr>
+<td>
+http://example.org/articles/8
+</td>
+<td>
+http://purl.org/dc/terms/title
+</td>
+<td>
+Capital
+</td>
+<td>
+en
+</td>
+</tr>
+</tbody>
+</table>
+<p>
+As
+the
+notion
+of
+ordered
+collections
+is
+rather
+important
+in
+data
+modeling,
+it
+is
+useful
+to
+have
+specific
+language
+support.
+In
+JSON-LD,
+a
+list
+may
+be
+represented
+using
+the
+<code>
+@list
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>
+as
+follows:
+</p>
+<del class="diff-old">{
+...
+ "@id": "http://example.org/people#joebob",
+ "foaf:nick":
+ {
+ "@list": [ "joe", "bob", "jaybee" ]
+ },
+...
+</del>
+<div class="example"><div class="example-title"><span>Example 43</span>: An ordered collection of values in JSON-LD</div><pre class="example">{
+<ins class="diff-chg">...
+ "@id": "http://example.org/people#joebob",
+ "foaf:nick":
+</ins> <span class="diff">{
+<ins class="diff-chg">
+ "@list": [ "joe", "bob", "jaybee" ]
+ }</span>,
+...
+</ins>
+}
+</pre>
+</div>
+<p>
+This
+describes
+the
+use
+of
+this
+<a href="#dfn-array" title="array" class="tref internalDFN">
+array
+</a>
+as
+being
+ordered,
+and
+order
+is
+maintained
+when
+processing
+a
+document.
+If
+every
+use
+of
+a
+given
+multi-valued
+property
+is
+a
+list,
+this
+may
+be
+abbreviated
+by
+setting
+<code>
+@container
+</code>
+to
+<code>
+@list
+</code>
+in
+the
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>:
+</p>
+<del class="diff-old">{
+ "@context":
+ {
+ ...
+ "nick":
+ {
+ "@id": "http://xmlns.com/foaf/0.1/nick",
+ "@container": "@list"
+ }
+ },
+...
+ "@id": "http://example.org/people#joebob",
+ "nick": ,
+...
+</del>
+<div class="example"><div class="example-title"><span>Example 44</span>: Specifying that a collection is ordered in the context</div><pre class="example">{
+ <span class="diff">"@context":
+<ins class="diff-chg"> {
+ ...
+ "nick":
+ {
+ "@id": "http://xmlns.com/foaf/0.1/nick",
+ "@container": "@list"
+ }
+ }</span>,
+...
+ "@id": "http://example.org/people#joebob",
+ "nick": <span class="diff">[ "joe", "bob", "jaybee" ]</span>,
+...
+</ins>
+}
+</pre>
+</div>
+<div class="note">
+<div class="note-title">
+<span>
+Note
+</span>
+</div>
+<p class="">
+List
+of
+lists
+are
+not
+allowed
+in
+this
+version
+of
+JSON-LD.
+This
+decision
+was
+made
+due
+to
+the
+extreme
+amount
+of
+added
+complexity
+when
+processing
+lists
+of
+lists.
+</p>
+</div>
+<p>
+While
+<code>
+@list
+</code>
+is
+used
+to
+describe
+<em>
+ordered
+<del class="diff-old">sets
+</del>
+<ins class="diff-chg">lists
+</ins>
+</em>,
+the
+<code>
+@set
+</code>
+keyword
+is
+used
+to
+describe
+<em>
+unordered
+sets
+</em>.
+The
+use
+of
+<code>
+@set
+</code>
+in
+the
+body
+of
+a
+JSON-LD
+document
+is
+optimized
+away
+when
+processing
+the
+document,
+as
+it
+is
+just
+syntactic
+sugar.
+However,
+<code>
+@set
+</code>
+is
+helpful
+when
+used
+within
+the
+context
+of
+a
+document.
+Values
+of
+terms
+associated
+with
+a
+<code>
+@set
+</code>
+or
+<code>
+@list
+</code>
+container
+are
+always
+represented
+in
+the
+form
+of
+an
+<a href="#dfn-array" title="array" class="tref internalDFN">
+array
+</a>,
+even
+if
+there
+is
+just
+a
+single
+value
+that
+would
+otherwise
+be
+optimized
+to
+a
+non-array
+form
+in
+compact
+form
+(see
+<a class="sec-ref" href="#compact-document-form">
+<span class="secno">
+<del class="diff-old">6.15
+</del>
+<ins class="diff-chg">6.16
+</ins>
+</span>
+<span class="sec-title">
+Compact
+Document
+Form
+</span>
+</a>
+).
+This
+makes
+post-processing
+of
+JSON-LD
+documents
+easier
+as
+the
+data
+is
+always
+in
+array
+form,
+even
+if
+the
+array
+only
+contains
+a
+single
+value.
+</p>
+<div class="note">
+<div class="note-title">
+<span>
+Note
+</span>
+</div>
+<p class="">
+The
+use
+of
+<code>
+@container
+</code>
+in
+the
+body
+of
+a
+JSON-LD
+document
+has
+no
+meaning
+and
+is
+not
+allowed
+by
+the
+JSON-LD
+grammar
+(see
+<a class="sec-ref" href="#json-ld-grammar">
+<span class="secno">
+B.
+</span>
+<span class="sec-title">
+JSON-LD
+Grammar
+</span>
+</a>
+).
+</p>
+</div>
+</section>
+<section id="embedding">
+<h3>
+<span class="secno">
+<del class="diff-old">6.10
+</del>
+<ins class="diff-chg">6.11
+</ins>
+</span>
+Embedding
+</h3>
+<p>
+<dfn id="dfn-embedding" title="embedding">
+Embedding
+</dfn>
+is
+a
+JSON-LD
+feature
+that
+allows
+an
+author
+to
+use
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+objects
+</a>
+as
+<a href="#dfn-property" title="property" class="tref internalDFN">
+property
+</a>
+values.
+This
+is
+a
+commonly
+used
+mechanism
+for
+creating
+a
+parent-child
+relationship
+between
+two
+<a href="#dfn-node" title="node" class="tref internalDFN">
+nodes
+</a>.
+</p>
+<p>
+The
+example
+shows
+two
+nodes
+related
+by
+a
+property
+from
+the
+first
+node:
+</p>
+<del class="diff-old"> {
+...
+ "name": "Manu Sporny",
+ "":
+ {
+ "",
+ "",
+ }
+...
+</del>
+ <div class="example"><div class="example-title"><span>Example 45</span>: Embedding a node object as property value of another node object</div><pre class="example">{
+<ins class="diff-chg">...
+ "name": "Manu Sporny",
+ "<span class="diff">knows</span>":
+ {
+ "<span class="diff">@type</span>": "<span class="diff">Person</span>",
+ "<span class="diff">name</span>": "<span class="diff">Gregg Kellogg</span>",
+ }
+...
+</ins>
+}
+</pre>
+</div>
+<p>
+A
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>,
+like
+the
+one
+used
+above,
+may
+be
+used
+in
+any
+value
+position
+in
+the
+body
+of
+a
+JSON-LD
+document.
+</p>
+</section>
+<section id="named-graphs">
+<h3>
+<span class="secno">
+<del class="diff-old">6.11
+</del>
+<ins class="diff-chg">6.12
+</ins>
+</span>
+Named
+Graphs
+</h3>
+<p>
+At
+times,
+it
+is
+necessary
+to
+make
+statements
+about
+a
+<a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">
+JSON-LD
+graph
+</a>
+itself,
+rather
+than
+just
+a
+single
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>.
+This
+can
+be
+done
+by
+grouping
+a
+set
+of
+<a href="#dfn-node" title="node" class="tref internalDFN">
+nodes
+</a>
+using
+the
+<code>
+@graph
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>.
+A
+developer
+may
+also
+name
+data
+expressed
+using
+the
+<code>
+@graph
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>
+by
+pairing
+it
+with
+an
+<code>
+@id
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>
+as
+shown
+in
+the
+following
+example:
+</p>
+<del class="diff-old"> {
+ "@context": {
+ "generatedAt": "http://www.w3.org/ns/prov#generatedAtTime",
+ "Person": "http://xmlns.com/foaf/0.1/Person",
+ "name": "http://xmlns.com/foaf/0.1/name",
+ "knows": "http://xmlns.com/foaf/0.1/knows",
+ "xsd": "http://www.w3.org/2001/XMLSchema#"
+ },
+ "@id": "http://example.org/graphs/73",
+ "generatedAt": { "@value": "2012-04-09", "@type": "xsd:date" },
+ "@graph":
+ [
+ {
+ "@id": "http://manu.sporny.org/i/public",
+ "@type": "Person",
+ "name": "Manu Sporny",
+ "knows": "http://greggkellogg.net/foaf#me"
+ },
+ {
+ "@id": "http://greggkellogg.net/foaf#me",
+ "@type": "Person",
+ "name": "Gregg Kellogg",
+ "knows": "http://manu.sporny.org/i/public"
+ }
+ ]
+</del>
+ <div class="example"><div class="example-title"><span>Example 46</span>: Identifying and making statements about a graph</div><pre class="example">{
+<ins class="diff-chg"> "@context": {
+ "generatedAt": "http://www.w3.org/ns/prov#generatedAtTime",
+ "Person": "http://xmlns.com/foaf/0.1/Person",
+ "name": "http://xmlns.com/foaf/0.1/name",
+ "knows": "http://xmlns.com/foaf/0.1/knows",
+ "xsd": "http://www.w3.org/2001/XMLSchema#"
+ },
+</ins> <span class="diff">"@id": "http://example.org/graphs/73",
+<ins class="diff-chg">
+ "generatedAt": { "@value": "2012-04-09", "@type": "xsd:date" },
+ "@graph":</span>
+ [
+ {
+ "@id": "http://manu.sporny.org/i/public",
+ "@type": "Person",
+ "name": "Manu Sporny",
+ "knows": "http://greggkellogg.net/foaf#me"
+ },
+ {
+ "@id": "http://greggkellogg.net/foaf#me",
+ "@type": "Person",
+ "name": "Gregg Kellogg",
+ "knows": "http://manu.sporny.org/i/public"
+ }
+ ]
+</ins>
+}
+</pre>
+</div>
+<p>
+The
+example
+above
+expresses
+a
+<em>
+named
+</em>
+<a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">
+JSON-LD
+graph
+</a>
+that
+is
+identified
+by
+the
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+<code>
+http://example.org/graphs/73
+</code>.
+That
+graph
+is
+composed
+of
+the
+statements
+about
+Manu
+and
+Gregg.
+Metadata
+about
+the
+graph
+itself
+is
+also
+expressed
+via
+the
+<code>
+generatedAt
+</code>
+property,
+which
+specifies
+when
+the
+graph
+was
+generated.
+An
+alternative
+view
+of
+the
+information
+above
+is
+represented
+in
+table
+form
+below:
+</p>
+<table class="example">
+<thead>
+<tr>
+<th>
+Graph
+</th>
+<th>
+Subject
+</th>
+<th>
+Property
+</th>
+<th>
+Value
+</th>
+<th>
+Value
+Type
+</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>
+http://example.org/graphs/73
+</td>
+<td>
+http://example.org/graphs/73
+</td>
+<td>
+http://www.w3.org/ns/prov#generatedAtTime
+</td>
+<td>
+2012-04-09
+</td>
+<td>
+http://www.w3.org/2001/XMLSchema#date
+</td>
+</tr>
+<tr>
+<td>
+http://example.org/graphs/73
+</td>
+<td>
+http://manu.sporny.org/i/public
+</td>
+<td>
+http://www.w3.org/2001/XMLSchema#type
+</td>
+<td>
+http://xmlns.com/foaf/0.1/Person
+</td>
+<td>
+</td>
+</tr>
+<tr>
+<td>
+http://example.org/graphs/73
+</td>
+<td>
+http://manu.sporny.org/i/public
+</td>
+<td>
+http://xmlns.com/foaf/0.1/name
+</td>
+<td>
+Manu
+Sporny
+</td>
+<td>
+</td>
+</tr>
+<tr>
+<td>
+http://example.org/graphs/73
+</td>
+<td>
+http://manu.sporny.org/i/public
+</td>
+<td>
+http://xmlns.com/foaf/0.1/knows
+</td>
+<td>
+http://greggkellogg.net/foaf#me
+</td>
+<td>
+</td>
+</tr>
+<tr>
+<td>
+http://example.org/graphs/73
+</td>
+<td>
+http://greggkellogg.net/foaf#me
+</td>
+<td>
+http://www.w3.org/2001/XMLSchema#type
+</td>
+<td>
+http://xmlns.com/foaf/0.1/Person
+</td>
+<td>
+</td>
+</tr>
+<tr>
+<td>
+http://example.org/graphs/73
+</td>
+<td>
+http://greggkellogg.net/foaf#me
+</td>
+<td>
+http://xmlns.com/foaf/0.1/name
+</td>
+<td>
+Gregg
+Kellogg
+</td>
+<td>
+</td>
+</tr>
+<tr>
+<td>
+http://example.org/graphs/73
+</td>
+<td>
+http://greggkellogg.net/foaf#me
+</td>
+<td>
+http://xmlns.com/foaf/0.1/knows
+</td>
+<td>
+http://manu.sporny.org/i/public
+</td>
+<td>
+</td>
+</tr>
+</tbody>
+</table>
+<p>
+When
+<del class="diff-old">@graph
+is
+used
+in
+</del>
+a
+<ins class="diff-new">JSON-LD
+</ins>
+document's
+top-level
+<ins class="diff-new">structure
+is
+an
+</ins><a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+object
+<del class="diff-old">which
+has
+</del>
+</a>
+<ins class="diff-chg">that
+contains
+</ins>
+no
+other
+<a href="#dfn-property" title="property" class="tref internalDFN">
+properties
+</a>
+<ins class="diff-new">than
+</ins><code><ins class="diff-new">
+@graph
+</ins></code><ins class="diff-new">
+and
+optionally
+</ins><code><ins class="diff-new">
+@context
+</ins></code><ins class="diff-new">
+(properties
+</ins>
+that
+are
+<ins class="diff-new">not
+</ins>
+mapped
+to
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+or
+a
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>
+<del class="diff-old">it
+</del>
+<ins class="diff-chg">are
+ignored),
+</ins><code><ins class="diff-chg">
+@graph
+</ins></code>
+is
+considered
+to
+express
+the
+otherwise
+implicit
+<a href="#dfn-default-graph" title="default-graph" class="tref internalDFN">
+default
+<del class="diff-old">graph.
+</del>
+<ins class="diff-chg">graph
+</ins></a>.
+This
+mechanism
+can
+be
+useful
+when
+a
+number
+of
+<a href="#dfn-node" title="node" class="tref internalDFN">
+nodes
+</a>
+<del class="diff-old">do
+not
+directly
+relate
+to
+one
+another
+through
+a
+property
+or
+where
+embedding
+</del>
+<ins class="diff-chg">exist
+at
+the
+document's
+top
+level
+that
+share
+the
+same
+</ins><a href="#dfn-context" title="context" class="tref internalDFN"><ins class="diff-chg">
+context
+</ins></a>.<ins class="diff-chg">
+The
+</ins><code><ins class="diff-chg">
+@graph
+</ins></code><ins class="diff-chg">
+keyword
+collects
+such
+nodes
+in
+an
+</ins><a href="#dfn-array" title="array" class="tref internalDFN"><ins class="diff-chg">
+array
+</ins>
+</a>
+<del class="diff-old">is
+not
+desirable
+to
+</del>
+<ins class="diff-chg">and
+allows
+</ins>
+the
+<del class="diff-old">application.
+For
+example:
+</del>
+<ins class="diff-chg">use
+of
+a
+shared
+context.
+</ins>
+</p>
+<del class="diff-old"> {
+ "@context": ...,
+ "":
+ [
+ {
+ "@id": "http://manu.sporny.org/i/public",
+ "@type": "foaf:Person",
+ "name": "Manu Sporny",
+ "knows": "http://greggkellogg.net/foaf#me"
+ },
+ {
+ "@id": "http://greggkellogg.net/foaf#me",
+ "@type": "foaf:Person",
+ "name": "Gregg Kellogg",
+ "knows": "http://manu.sporny.org/i/public"
+ }
+ ]
+</del>
+ <div class="example"><div class="example-title"><span>Example 47</span>: Using @graph to explicitly express the default graph</div><pre class="example">{
+<ins class="diff-chg"> "@context": ...,
+ "<span class="diff">@graph</span>":
+ [
+ {
+ "@id": "http://manu.sporny.org/i/public",
+ "@type": "foaf:Person",
+ "name": "Manu Sporny",
+ "knows": "http://greggkellogg.net/foaf#me"
+ },
+ {
+ "@id": "http://greggkellogg.net/foaf#me",
+ "@type": "foaf:Person",
+ "name": "Gregg Kellogg",
+ "knows": "http://manu.sporny.org/i/public"
+ }
+ ]
+</ins>
+}
+</pre>
+</div>
+<p>
+In
+this
+case,
+embedding
+doesn't
+work
+as
+each
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>
+references
+the
+other.
+<del class="diff-old">Using
+the
+@graph
+keyword
+allows
+multiple
+nodes
+to
+be
+defined
+within
+an
+array
+,
+and
+allows
+the
+use
+of
+a
+shared
+context
+.
+</del>
+This
+is
+equivalent
+to
+using
+multiple
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+objects
+</a>
+in
+array
+and
+defining
+the
+<code>
+@context
+</code>
+within
+each
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>:
+</p>
+<del class="diff-old"> [
+ {
+
+ "@id": "http://manu.sporny.org/i/public",
+ "@type": "foaf:Person",
+ "name": "Manu Sporny",
+ "knows": "http://greggkellogg.net/foaf#me"
+ },
+ {
+
+ "@id": "http://greggkellogg.net/foaf#me",
+ "@type": "foaf:Person",
+ "name": "Gregg Kellogg",
+ "knows": "http://manu.sporny.org/i/public"
+ }
+</del>
+ <div class="example"><div class="example-title"><span>Example 48</span>: Context needs to be duplicated if @graph is not used</div><pre class="example">[
+<ins class="diff-chg"> {
+</ins> <span class="diff">"@context": ...,</span>
+<ins class="diff-chg">
+ "@id": "http://manu.sporny.org/i/public",
+ "@type": "foaf:Person",
+ "name": "Manu Sporny",
+ "knows": "http://greggkellogg.net/foaf#me"
+ },
+ {
+</ins> <span class="diff">"@context": ...,</span>
+<ins class="diff-chg">
+ "@id": "http://greggkellogg.net/foaf#me",
+ "@type": "foaf:Person",
+ "name": "Gregg Kellogg",
+ "knows": "http://manu.sporny.org/i/public"
+ }
+</ins>
+]
+</pre>
+</div>
+</section>
+<section id="identifying-blank-nodes">
+<h3>
+<span class="secno">
+<del class="diff-old">6.12
+</del>
+<ins class="diff-chg">6.13
+</ins>
+</span>
+Identifying
+Blank
+Nodes
+</h3>
+<p>
+At
+times,
+it
+becomes
+necessary
+to
+be
+able
+to
+express
+information
+without
+being
+able
+to
+uniquely
+identify
+the
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>.
+This
+type
+of
+node
+is
+called
+a
+<a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">
+blank
+node
+</a>
+(see
+<cite>
+<a href="http://www.w3.org/TR/rdf11-concepts/#section-blank-nodes">
+Section
+3.4:
+Blank
+Nodes
+</a>
+</cite>
+of
+[
+<cite>
+<a href="#bib-RDF-CONCEPTS" class="bibref">
+RDF-CONCEPTS
+</a>
+</cite>
+]).
+In
+JSON-LD,
+<a href="#dfn-blank-node-identifier" title="blank-node-identifier" class="tref internalDFN">
+blank
+node
+identifiers
+</a>
+are
+automatically
+created
+if
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+is
+not
+specified
+using
+the
+<code>
+@id
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>.
+However,
+authors
+may
+provide
+identifiers
+for
+<a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">
+blank
+nodes
+</a>
+by
+using
+the
+special
+<code>
+_
+</code>
+(underscore)
+<a href="#dfn-prefix" title="prefix" class="tref internalDFN">
+prefix
+</a>.
+This
+allows
+one
+to
+reference
+the
+node
+locally
+within
+the
+document,
+but
+makes
+it
+impossible
+to
+reference
+the
+node
+from
+an
+external
+document.
+The
+<a href="#dfn-blank-node-identifier" title="blank-node-identifier" class="tref internalDFN">
+blank
+node
+identifier
+</a>
+is
+scoped
+to
+the
+document
+in
+which
+it
+is
+used.
+</p>
+<del class="diff-old"> {
+...
+ "@id": "",
+...
+</del>
+ <div class="example"><div class="example-title"><span>Example 49</span>: Specifying a local blank node identifier</div><pre class="example">{
+<ins class="diff-chg">...
+ "@id": "<span class="diff">_:foo</span>",
+...
+</ins>
+}
+</pre>
+</div>
+<p>
+The
+example
+above
+would
+set
+the
+node
+to
+<code>
+_:foo
+</code>,
+which
+can
+then
+be
+used
+elsewhere
+in
+the
+JSON-LD
+document
+to
+refer
+back
+to
+the
+<a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">
+blank
+node
+</a>.
+If
+a
+developer
+finds
+that
+they
+refer
+to
+the
+<a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">
+blank
+node
+</a>
+more
+than
+once,
+they
+should
+consider
+naming
+the
+node
+using
+a
+dereferenceable
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+so
+that
+it
+can
+also
+be
+referenced
+from
+other
+documents.
+</p>
+</section>
+<section id="aliasing-keywords">
+<h3>
+<span class="secno">
+<del class="diff-old">6.13
+</del>
+<ins class="diff-chg">6.14
+</ins>
+</span>
+Aliasing
+Keywords
+</h3>
+<p>
+Each
+of
+the
+JSON-LD
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keywords
+</a>,
+except
+for
+<code>
+@context
+</code>,
+may
+be
+aliased
+to
+application-specific
+keywords.
+This
+feature
+allows
+legacy
+JSON
+content
+to
+be
+utilized
+by
+JSON-LD
+by
+re-using
+JSON
+keys
+that
+already
+exist
+in
+legacy
+documents.
+This
+feature
+also
+allows
+developers
+to
+design
+domain-specific
+implementations
+using
+only
+the
+JSON-LD
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>.
+</p>
+<del class="diff-old"> {
+ "@context":
+ {
+ ,
+ ,
+ "name": "http://xmlns.com/foaf/0.1/name"
+ },
+ "": "http://example.com/about#gregg",
+ "": "http://xmlns.com/foaf/0.1/Person",
+ "name": "Gregg Kellogg"
+</del>
+ <div class="example"><div class="example-title"><span>Example 50</span>: Aliasing keywords</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+</ins> <span class="diff">"url": "@id"</span>,
+ <span class="diff">"a": "@type"</span>,
+<ins class="diff-chg">
+ "name": "http://xmlns.com/foaf/0.1/name"
+ },
+ "<span class="diff">url</span>": "http://example.com/about#gregg",
+ "<span class="diff">a</span>": "http://xmlns.com/foaf/0.1/Person",
+ "name": "Gregg Kellogg"
+</ins>
+}
+</pre>
+</div>
+<p>
+In
+the
+example
+above,
+the
+<code>
+@id
+</code>
+and
+<code>
+@type
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keywords
+</a>
+have
+been
+given
+the
+aliases
+<strong>
+url
+</strong>
+and
+<strong>
+a
+</strong>,
+respectively.
+</p>
+<p>
+Since
+keywords
+cannot
+be
+redefined,
+they
+can
+also
+not
+be
+aliased
+to
+other
+keywords.
+Every
+statement
+in
+the
+context
+having
+a
+keyword
+as
+the
+key
+(as
+in
+<code style="white-space: nowrap">
+{
+"@type":
+...
+}
+</code>
+)
+will
+be
+ignored
+when
+being
+processed.
+</p>
+</section>
+<section id="expanded-document-form">
+<h3>
+<span class="secno">
+<del class="diff-old">6.14
+</del>
+<ins class="diff-chg">6.15
+</ins>
+</span>
+Expanded
+Document
+Form
+</h3>
+<p>
+The
+JSON-LD
+Algorithms
+and
+API
+specification
+[
+<cite>
+<a href="#bib-JSON-LD-API" class="bibref">
+JSON-LD-API
+</a>
+</cite>
+]
+defines
+a
+method
+for
+<em>
+expanding
+</em>
+a
+JSON-LD
+document.
+Expansion
+is
+the
+process
+of
+taking
+a
+JSON-LD
+document
+and
+applying
+a
+<code>
+@context
+</code>
+such
+that
+all
+IRIs,
+types,
+and
+values
+are
+expanded
+so
+that
+the
+<code>
+@context
+</code>
+is
+no
+longer
+necessary.
+</p>
+<p>
+For
+example,
+assume
+the
+following
+JSON-LD
+input
+document:
+</p>
+<del class="diff-old">{
+ "@context":
+ {
+ "name": "http://xmlns.com/foaf/0.1/name",
+ "homepage": {
+ "@id": "http://xmlns.com/foaf/0.1/homepage",
+ "@type": "@id"
+ }
+ },
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/"
+</del>
+<div class="example"><div class="example-title"><span>Example 51</span>: Sample JSON-LD document</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+ "name": "http://xmlns.com/foaf/0.1/name",
+ "homepage": {
+ "@id": "http://xmlns.com/foaf/0.1/homepage",
+ "@type": "@id"
+ }
+ },
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/"
+</ins>
+}
+</pre>
+</div>
+<p>
+Running
+the
+JSON-LD
+Expansion
+algorithm
+against
+the
+JSON-LD
+input
+document
+provided
+above
+would
+result
+in
+the
+following
+output:
+</p>
+<del class="diff-old">[
+ {
+ "http://xmlns.com/foaf/0.1/name": [
+ { "@value": "Manu Sporny" }
+ ],
+ "http://xmlns.com/foaf/0.1/homepage": [
+ { "@id": "http://manu.sporny.org/" }
+ ]
+ }
+</del>
+<div class="example"><div class="example-title"><span>Example 52</span>: Expanded form for the previous example</div><pre class="example">[
+<ins class="diff-chg"> {
+ "http://xmlns.com/foaf/0.1/name": [
+ { "@value": "Manu Sporny" }
+ ],
+ "http://xmlns.com/foaf/0.1/homepage": [
+ { "@id": "http://manu.sporny.org/" }
+ ]
+ }
+</ins>
+]
+</pre>
+</div>
+<p>
+Expanded
+document
+form
+is
+useful
+when
+an
+application
+has
+to
+process
+input
+data
+in
+a
+deterministic
+form.
+It
+has
+been
+optimized
+to
+ensure
+that
+the
+code
+that
+developers
+have
+to
+write
+is
+minimized
+compared
+to
+the
+code
+that
+would
+have
+to
+be
+written
+to
+operate
+on
+<a class="sec-ref" href="#compact-document-form">
+<span class="secno">
+<del class="diff-old">6.15
+</del>
+<ins class="diff-chg">6.16
+</ins>
+</span>
+<span class="sec-title">
+Compact
+Document
+Form
+</span>
+</a>.
+</p>
+</section>
+<section id="compact-document-form">
+<h3>
+<span class="secno">
+<del class="diff-old">6.15
+</del>
+<ins class="diff-chg">6.16
+</ins>
+</span>
+Compact
+Document
+Form
+</h3>
+<p>
+The
+JSON-LD
+Algorithms
+and
+API
+specification
+[
+<cite>
+<a href="#bib-JSON-LD-API" class="bibref">
+JSON-LD-API
+</a>
+</cite>
+]
+defines
+a
+method
+for
+<em>
+compacting
+</em>
+a
+JSON-LD
+document.
+Compaction
+is
+the
+process
+of
+taking
+a
+JSON-LD
+document
+and
+applying
+a
+context
+such
+that
+a
+very
+compact
+form
+of
+the
+document
+is
+generated.
+At
+times,
+a
+JSON-LD
+document
+may
+be
+received
+that
+is
+not
+in
+its
+most
+compact
+form.
+The
+JSON-LD
+Algorithms,
+via
+an
+API,
+provides
+a
+way
+to
+compact
+a
+JSON-LD
+document.
+</p>
+<p>
+For
+example,
+assume
+the
+following
+JSON-LD
+input
+document:
+</p>
+<del class="diff-old">[
+ {
+ "http://xmlns.com/foaf/0.1/name": [ "Manu Sporny" ],
+ "http://xmlns.com/foaf/0.1/homepage": [
+ {
+ "@id": "http://manu.sporny.org/"
+ }
+ ]
+ }
+</del>
+<div class="example"><div class="example-title"><span>Example 53</span>: Sample expanded JSON-LD document</div><pre class="example">[
+<ins class="diff-chg"> {
+ "http://xmlns.com/foaf/0.1/name": [ "Manu Sporny" ],
+ "http://xmlns.com/foaf/0.1/homepage": [
+ {
+ "@id": "http://manu.sporny.org/"
+ }
+ ]
+ }
+</ins>
+]
+</pre>
+</div>
+<p>
+Additionally,
+assume
+the
+following
+developer-supplied
+JSON-LD
+context:
+</p>
+<del class="diff-old">{
+ "@context": {
+ "name": "http://xmlns.com/foaf/0.1/name",
+ "homepage": {
+ "@id": "http://xmlns.com/foaf/0.1/homepage",
+ "@type": "@id"
+ }
+ }
+</del>
+<div class="example"><div class="example-title"><span>Example 54</span>: Sample context</div><pre class="example">{
+<ins class="diff-chg"> "@context": {
+ "name": "http://xmlns.com/foaf/0.1/name",
+ "homepage": {
+ "@id": "http://xmlns.com/foaf/0.1/homepage",
+ "@type": "@id"
+ }
+ }
+</ins>
+}
+</pre>
+</div>
+<p>
+Running
+the
+JSON-LD
+Compaction
+algorithm
+given
+the
+context
+supplied
+above
+against
+the
+JSON-LD
+input
+document
+provided
+above
+would
+result
+in
+the
+following
+output:
+</p>
+<del class="diff-old">{
+ "@context": {
+ "name": "http://xmlns.com/foaf/0.1/name",
+ "homepage": {
+ "@id": "http://xmlns.com/foaf/0.1/homepage",
+ "@type": "@id"
+ }
+ },
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/"
+</del>
+<div class="example"><div class="example-title"><span>Example 55</span>: Compact form of the sample document once sample context has been applied</div><pre class="example">{
+<ins class="diff-chg"> "@context": {
+ "name": "http://xmlns.com/foaf/0.1/name",
+ "homepage": {
+ "@id": "http://xmlns.com/foaf/0.1/homepage",
+ "@type": "@id"
+ }
+ },
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/"
+</ins>
+}
+</pre>
+</div>
+<p>
+The
+compaction
+algorithm
+enables
+a
+developer
+to
+map
+any
+document
+into
+an
+application-specific
+compacted
+form.
+The
+process
+consists
+of
+expanding
+the
+document
+(see
+<a class="sec-ref" href="#expanded-document-form">
+<span class="secno">
+<del class="diff-old">6.14
+</del>
+<ins class="diff-chg">6.15
+</ins>
+</span>
+<span class="sec-title">
+Expanded
+Document
+Form
+</span>
+</a>
+)
+and
+then
+using
+a
+developer-supplied
+context
+to
+compact
+the
+expanded
+document.
+While
+the
+context
+provided
+above
+mapped
+<code>
+http://xmlns.com/foaf/0.1/name
+</code>
+to
+<strong>
+name
+</strong>,
+it
+could
+have
+also
+mapped
+it
+to
+any
+arbitrary
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+provided
+by
+the
+developer.
+This
+powerful
+mechanism
+allows
+the
+developer
+to
+re-shape
+the
+incoming
+JSON
+data
+into
+a
+format
+that
+is
+optimized
+for
+their
+application.
+</p>
+</section>
+<section id="data-indexing">
+<h3>
+<span class="secno">
+<del class="diff-old">6.16
+</del>
+<ins class="diff-chg">6.17
+</ins>
+</span>
+Data
+Indexing
+</h3>
+<p>
+Databases
+are
+typically
+used
+to
+make
+access
+to
+data
+more
+efficient.
+Developers
+often
+extend
+this
+sort
+of
+functionality
+into
+their
+application
+data
+to
+deliver
+similar
+performance
+gains.
+Often
+this
+data
+does
+not
+have
+any
+meaning
+from
+a
+Linked
+Data
+standpoint,
+but
+is
+still
+useful
+for
+an
+application.
+</p>
+<p>
+JSON-LD
+introduces
+the
+notion
+of
+<a href="#dfn-index-map" title="index-map" class="tref internalDFN">
+index
+maps
+</a>
+that
+can
+be
+used
+to
+structure
+data
+into
+a
+form
+that
+is
+more
+efficient
+to
+access.
+The
+data
+indexing
+feature
+allows
+an
+author
+to
+structure
+data
+using
+a
+simpley
+key-value
+map
+where
+the
+keys
+do
+not
+map
+to
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>.
+This
+enables
+direct
+access
+to
+data
+instead
+of
+having
+to
+scan
+an
+array
+in
+search
+of
+a
+specific
+item.
+In
+JSON-LD
+such
+data
+can
+be
+specified
+by
+associating
+the
+<code>
+@index
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>
+with
+a
+<code>
+@container
+</code>
+declaration
+in
+the
+context:
+</p>
+<del class="diff-old"> {
+ "@context":
+ {
+ "schema": "http://schema.org/",
+ "name": "schema:name",
+ "body": "schema:articleBody",
+ "words": "schema:wordCount",
+ "post": {
+ "@id": "schema:blogPost",
+
+ }
+ },
+ "@id": "http://example.com/",
+ "@type": "schema:Blog",
+ "name": "World Financial News",
+ "post": {
+ "en": {
+ "@id": "http://example.com/posts/1/en",
+ "body": "World commodities were up today with heavy trading of crude oil...",
+ "words": 1539
+ },
+ "de": {
+ "@id": "http://example.com/posts/1/de",
+ "body": "Die Werte an Warenbörsen stiegen im Sog eines starken Handels von Rohöl...",
+ "words": 1204
+ }
+ }
+</del>
+ <div class="example"><div class="example-title"><span>Example 56</span>: Indexing data in JSON-LD</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+ "schema": "http://schema.org/",
+ "name": "schema:name",
+ "body": "schema:articleBody",
+ "words": "schema:wordCount",
+ "post": {
+ "@id": "schema:blogPost",
+</ins> <span class="diff">"@container": "@index"</span>
+<ins class="diff-chg">
+ }
+ },
+ "@id": "http://example.com/",
+ "@type": "schema:Blog",
+ "name": "World Financial News",
+</ins> <span class="diff">"post": {
+<ins class="diff-chg">
+ "en": {
+ "@id": "http://example.com/posts/1/en",
+ "body": "World commodities were up today with heavy trading of crude oil...",
+ "words": 1539
+ },
+ "de": {
+ "@id": "http://example.com/posts/1/de",
+ "body": "Die Werte an Warenbörsen stiegen im Sog eines starken Handels von Rohöl...",
+ "words": 1204
+ }</span>
+ }
+</ins>
+}
+</pre>
+</div>
+<p>
+In
+the
+example
+above,
+the
+<strong>
+blogPost
+</strong>
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+has
+been
+marked
+as
+an
+<a href="#dfn-index-map" title="index-map" class="tref internalDFN">
+index
+map
+</a>.
+The
+<strong>
+en
+</strong>,
+<strong>
+de
+</strong>,
+and
+<strong>
+ja
+</strong>
+keys
+will
+be
+ignored
+semantically,
+but
+preserved
+syntactically,
+by
+the
+JSON-LD
+Processor.
+This
+allows
+a
+developer
+to
+access
+the
+German
+version
+of
+the
+<strong>
+blogPost
+</strong>
+using
+the
+following
+code
+snippet:
+<code>
+obj.blogPost.de
+</code>.
+</p>
+<p>
+The
+interpretation
+of
+the
+data
+above
+is
+expressed
+in
+the
+table
+below.
+Note
+how
+the
+index
+keys
+do
+not
+appear
+in
+the
+Linked
+Data
+below,
+but
+would
+continue
+to
+exist
+if
+the
+document
+were
+compacted
+or
+expanded
+(see
+<a class="sec-ref" href="#compact-document-form">
+<span class="secno">
+<del class="diff-old">6.15
+</del>
+<ins class="diff-chg">6.16
+</ins>
+</span>
+<span class="sec-title">
+Compact
+Document
+Form
+</span>
+</a>
+and
+<a class="sec-ref" href="#expanded-document-form">
+<span class="secno">
+<del class="diff-old">6.14
+</del>
+<ins class="diff-chg">6.15
+</ins>
+</span>
+<span class="sec-title">
+Expanded
+Document
+Form
+</span>
+</a>
+)
+using
+a
+JSON-LD
+processor:
+</p>
+<table class="example">
+<thead>
+<tr>
+<th>
+Subject
+</th>
+<th>
+Property
+</th>
+<th>
+Value
+</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>
+http://example.com/
+</td>
+<td>
+http://www.w3.org/1999/02/22-rdf-syntax-ns#type
+</td>
+<td>
+http://schema.org/Blog
+</td>
+</tr>
+<tr>
+<td>
+http://example.com/
+</td>
+<td>
+http://schema.org/name
+</td>
+<td>
+World
+Financial
+News
+</td>
+</tr>
+<tr>
+<td>
+http://example.com/
+</td>
+<td>
+http://schema.org/blogPost
+</td>
+<td>
+http://example.com/posts/1/en
+</td>
+</tr>
+<tr>
+<td>
+http://example.com/
+</td>
+<td>
+http://schema.org/blogPost
+</td>
+<td>
+http://example.com/posts/1/de
+</td>
+</tr>
+<tr>
+<td>
+http://example.com/posts/1/en
+</td>
+<td>
+http://schema.org/articleBody
+</td>
+<td>
+World
+commodities
+were
+up
+today
+with
+heavy
+trading
+of
+crude
+oil...
+</td>
+</tr>
+<tr>
+<td>
+http://example.com/posts/1/en
+</td>
+<td>
+http://schema.org/wordCount
+</td>
+<td>
+1539
+</td>
+</tr>
+<tr>
+<td>
+http://example.com/posts/1/de
+</td>
+<td>
+http://schema.org/articleBody
+</td>
+<td>
+Die
+Werte
+an
+Warenbörsen
+stiegen
+im
+Sog
+eines
+starken
+Handels
+von
+Rohöl...
+</td>
+</tr>
+<tr>
+<td>
+http://example.com/posts/1/de
+</td>
+<td>
+http://schema.org/wordCount
+</td>
+<td>
+1204
+</td>
+</tr>
+</tbody>
+</table>
+</section>
+</section>
+<section id="data-model" class="appendix normative">
+<h2>
+<span class="secno">
+A.
+</span>
+Data
+Model
+</h2>
+<p>
+JSON-LD
+is
+a
+serialization
+format
+for
+<a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">
+Linked
+Data
+</a>
+based
+on
+JSON.
+It
+is
+therefore
+important
+to
+distinguish
+between
+the
+syntax,
+which
+is
+defined
+by
+JSON
+in
+[
+<cite>
+<a href="#bib-RFC4627" class="bibref">
+RFC4627
+</a>
+</cite>
+],
+and
+<dfn id="dfn-json-ld-data-model" title="json-ld-data-model">
+JSON-LD's
+data
+model
+</dfn>
+which
+is
+defined
+as
+follows:
+</p>
+<ul>
+<li>
+A
+<dfn id="dfn-json-ld-document" title="json-ld-document">
+JSON-LD
+document
+</dfn>
+serializes
+a
+collection
+of
+<a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">
+JSON-LD
+graphs
+</a>
+and
+comprises
+exactly
+one
+<dfn id="dfn-default-graph" title="default-graph">
+default
+graph
+</dfn>
+and
+zero
+or
+more
+<dfn id="dfn-named-graph" title="named-graph">
+named
+graphs
+</dfn>.
+</li>
+<li>
+The
+<a href="#dfn-default-graph" title="default-graph" class="tref internalDFN">
+default
+graph
+</a>
+does
+not
+have
+a
+name
+and
+<em title="may" class="rfc2119">
+may
+</em>
+be
+empty.
+</li>
+<li>
+Each
+<a href="#dfn-named-graph" title="named-graph" class="tref internalDFN">
+named
+graph
+</a>
+is
+a
+pair
+consisting
+of
+<del class="diff-old">a
+</del>
+<ins class="diff-chg">an
+</ins><a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier"><ins class="diff-chg">
+IRI
+</ins></abbr></a><ins class="diff-chg">
+or
+</ins><a href="#dfn-blank-node-identifier" title="blank-node-identifier" class="tref internalDFN"><ins class="diff-chg">
+blank
+node
+identifier
+</ins></a><ins class="diff-chg">
+(the
+</ins><dfn id="dfn-graph-name" title="graph-name">
+graph
+name
+</dfn>
+<ins class="diff-new">)
+</ins>
+and
+a
+<a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">
+JSON-LD
+graph
+</a>.
+<del class="diff-old">The
+</del>
+<ins class="diff-chg">Whenever
+possible,
+the
+</ins><a href="#dfn-graph-name" title="graph-name" class="tref internalDFN">
+graph
+name
+</a>
+<em title="should" class="rfc2119">
+should
+</em>
+be
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+<del class="diff-old">or
+blank
+node
+identifier
+</del>
+</a>.
+</li>
+<li>
+A
+<dfn id="dfn-json-ld-graph" title="json-ld-graph">
+JSON-LD
+graph
+</dfn>
+is
+a
+labeled
+directed
+<del class="diff-old">graph
+containing
+</del>
+<ins class="diff-chg">graph,
+i.e.,
+</ins>
+a
+set
+of
+<del class="diff-old">zero
+or
+more
+</del>
+<a href="#dfn-node" title="node" class="tref internalDFN">
+nodes
+</a>
+connected
+by
+<a href="#dfn-edge" title="edge" class="tref internalDFN">
+edges
+</a>.
+</li>
+<li>
+Every
+<dfn id="dfn-edge" title="edge">
+edge
+</dfn>
+has
+a
+direction
+associated
+with
+it
+and
+is
+labeled
+with
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+or
+a
+<a href="#dfn-blank-node-identifier" title="blank-node-identifier" class="tref internalDFN">
+blank
+node
+identifier
+</a>.
+Within
+the
+JSON-LD
+syntax
+these
+edge
+labels
+are
+called
+<dfn id="dfn-property" title="property">
+properties
+</dfn>.
+<ins class="diff-new">Whenever
+possible,
+an
+</ins><a href="#dfn-edge" title="edge" class="tref internalDFN"><ins class="diff-new">
+edge
+</ins></a><em title="should" class="rfc2119"><ins class="diff-new">
+should
+</ins></em><ins class="diff-new">
+be
+labeled
+with
+an
+</ins><a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier"><ins class="diff-new">
+IRI
+</ins></abbr></a>.
+</li>
+<li>
+Every
+<dfn id="dfn-node" title="node">
+node
+</dfn>
+is
+<del class="diff-old">either
+</del>
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+a
+<a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">
+blank
+node
+</a>,
+a
+<a href="#dfn-json-ld-value" title="json-ld-value" class="tref internalDFN">
+JSON-LD
+value
+</a>,
+or
+a
+<a href="#dfn-list" title="list" class="tref internalDFN">
+list
+</a>.
+</li>
+<li>
+A
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>
+having
+an
+outgoing
+edge
+<em title="must" class="rfc2119">
+must
+</em>
+be
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+or
+a
+<a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">
+blank
+node
+</a>.
+</li>
+<li>
+A
+<a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">
+JSON-LD
+graph
+</a>
+<em title="must not" class="rfc2119">
+must
+not
+</em>
+contain
+unconnected
+<a href="#dfn-node" title="node" class="tref internalDFN">
+nodes
+</a>,
+i.e.,
+nodes
+which
+are
+not
+connected
+by
+an
+<a href="#dfn-edge" title="edge" class="tref internalDFN">
+edge
+</a>
+to
+any
+other
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>.
+</li>
+<li>
+An
+<dfn id="dfn-iri" title="iri">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</dfn>
+(Internationalized
+Resource
+Identifier)
+is
+a
+string
+that
+conforms
+to
+the
+syntax
+defined
+in
+[
+<cite>
+<a href="#bib-RFC3987" class="bibref">
+RFC3987
+</a>
+</cite>
+].
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>
+used
+within
+a
+<a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">
+JSON-LD
+graph
+</a>
+<em title="should" class="rfc2119">
+should
+</em>
+return
+a
+<a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">
+Linked
+Data
+</a>
+document
+describing
+the
+resource
+denoted
+by
+that
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+when
+being
+dereferenced.
+</li>
+<li>
+A
+<dfn id="dfn-blank-node" title="blank-node">
+blank
+node
+</dfn>
+is
+a
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>
+which
+is
+<del class="diff-old">not
+</del>
+<ins class="diff-chg">neither
+</ins>
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+<ins class="diff-new">nor
+a
+</ins><a href="#dfn-json-ld-value" title="json-ld-value" class="tref internalDFN"><ins class="diff-new">
+JSON-LD
+value
+</ins></a>,<ins class="diff-new">
+or
+a
+</ins><a href="#dfn-list" title="list" class="tref internalDFN"><ins class="diff-new">
+list
+</ins>
+</a>.
+A
+blank
+node
+<em title="may" class="rfc2119">
+may
+</em>
+be
+identified
+using
+a
+<a href="#dfn-blank-node-identifier" title="blank-node-identifier" class="tref internalDFN">
+blank
+node
+identifier
+</a>.
+</li>
+<li>
+A
+<dfn id="dfn-blank-node-identifier" title="blank-node-identifier">
+blank
+node
+identifier
+</dfn>
+is
+a
+string
+that
+can
+be
+used
+as
+an
+identifier
+for
+a
+<a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">
+blank
+node
+</a>
+within
+the
+scope
+of
+a
+<a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">
+JSON-LD
+document
+</a>.
+Blank
+node
+identifiers
+begin
+with
+<code>
+_:
+</code>.
+</li>
+<li>
+A
+<dfn id="dfn-json-ld-value" title="json-ld-value">
+JSON-LD
+value
+</dfn>
+is
+a
+<a href="#dfn-string" title="string" class="tref internalDFN">
+string
+</a>,
+a
+<a href="#dfn-number" title="number" class="tref internalDFN">
+number
+</a>,
+<a href="#dfn-true" title="true" class="tref internalDFN">
+true
+</a>
+or
+<a href="#dfn-false" title="false" class="tref internalDFN">
+false
+</a>,
+a
+<a href="#dfn-typed-value" title="typed-value" class="tref internalDFN">
+typed
+value
+</a>,
+or
+a
+<a href="#dfn-language-tagged-string" title="language-tagged-string" class="tref internalDFN">
+language-tagged
+string
+</a>.
+</li>
+<li>
+A
+<dfn id="dfn-typed-value" title="typed-value">
+typed
+value
+</dfn>
+consists
+of
+a
+value,
+which
+is
+a
+string,
+and
+a
+type,
+which
+is
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+<del class="diff-old">.
+</del>
+</abbr>
+</a>.
+</li>
+<li>
+A
+<dfn id="dfn-language-tagged-string" title="language-tagged-string">
+language-tagged
+string
+</dfn>
+consists
+of
+a
+string
+and
+a
+non-empty
+language
+tag
+as
+defined
+by
+[
+<cite>
+<a href="#bib-BCP47" class="bibref">
+BCP47
+</a>
+</cite>
+].
+The
+language
+tag
+<em title="must" class="rfc2119">
+must
+</em>
+be
+well-formed
+according
+to
+section
+<a href="http://tools.ietf.org/html/bcp47#section-2.2.9">
+2.2.9
+</a>
+of
+[
+<cite>
+<a href="#bib-BCP47" class="bibref">
+BCP47
+</a>
+</cite>
+],
+and
+<em title="must" class="rfc2119">
+must
+</em>
+be
+lowercase.
+</li>
+<li>
+A
+<dfn id="dfn-list" title="list">
+list
+</dfn>
+is
+an
+ordered
+sequence
+of
+zero
+or
+more
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>,
+<a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">
+blank
+nodes
+</a>,
+and
+<a href="#dfn-json-ld-value" title="json-ld-value" class="tref internalDFN">
+JSON-LD
+values
+</a>.
+</li>
+</ul>
+<div class="issue">
+<div class="issue-title">
+<a href="https://github.com/json-ld/json-ld.org/issues/217">
+<span>
+Issue
+<del class="diff-old">1
+</del>
+<ins class="diff-chg">217
+</ins>
+</span>
+</a>
+</div>
+<p class="">
+In
+contrast
+to
+the
+RDF
+data
+model
+as
+defined
+in
+[
+<cite>
+<a href="#bib-RDF-CONCEPTS" class="bibref">
+RDF-CONCEPTS
+</a>
+</cite>
+],
+JSON-LD
+allows
+blank
+nodes
+as
+property
+labels
+and
+graph
+names.
+This
+feature
+is
+controversial
+in
+the
+RDF
+WG
+and
+may
+be
+removed
+in
+the
+future.
+</p>
+</div>
+<p>
+<a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">
+JSON-LD
+documents
+</a>
+<em title="may" class="rfc2119">
+may
+</em>
+contain
+data
+that
+cannot
+be
+represented
+by
+the
+<a href="#dfn-json-ld-data-model" title="json-ld-data-model" class="tref internalDFN">
+data
+model
+</a>
+defined
+above.
+Unless
+otherwise
+specified,
+such
+data
+is
+ignored
+when
+a
+<a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">
+JSON-LD
+document
+</a>
+is
+being
+processed.
+This
+means,
+e.g.,
+that
+properties
+which
+are
+not
+mapped
+to
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+or
+<a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">
+blank
+node
+</a>
+will
+be
+ignored.
+</p>
+<p style="text-align: center">
+<img src="linked-data-graph.png" title="An illustration of JSON-LD's data model">
+</p>
+<p style="text-align: center">
+Figure 1:
+An
+illustration
+of
+JSON-LD's
+data
+model.
+</p>
+</section>
+<section id="json-ld-grammar" class="appendix normative">
+<h2>
+<span class="secno">
+B.
+</span>
+JSON-LD
+Grammar
+</h2>
+<em>
+This
+section
+is
+normative
+</em>
+<p>
+This
+appendix
+restates
+the
+syntactic
+conventions
+described
+in
+the
+previous
+sections
+more
+formally.
+</p>
+<div class="note">
+<div class="note-title">
+<span>
+Note
+</span>
+</div>
+<p class="">
+The
+JSON-LD
+context
+allows
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keywords
+</a>
+<a class="sec-ref" href="#aliasing-keywords">
+<span class="secno">
+<del class="diff-old">6.13
+</del>
+<ins class="diff-chg">6.14
+</ins>
+</span>
+<span class="sec-title">
+Aliasing
+Keywords
+</span>
+</a>
+).
+Whenever
+a
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>
+is
+discussed
+in
+this
+grammar,
+the
+statements
+also
+apply
+to
+an
+alias
+for
+that
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>.
+For
+example,
+if
+the
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>
+defines
+the
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+<code>
+id
+</code>
+as
+an
+alias
+for
+<code>
+@id
+</code>,
+that
+alias
+may
+be
+legitimately
+used
+as
+a
+substitution
+for
+<code>
+@id
+</code>.
+Note
+that
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>
+aliases
+are
+not
+expanded
+during
+context
+processing.
+</p>
+</div>
+<p>
+A
+<a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">
+JSON-LD
+document
+</a>
+<em title="must" class="rfc2119">
+must
+</em>
+be
+a
+valid
+JSON
+document
+as
+described
+in
+[
+<cite>
+<a href="#bib-RFC4627" class="bibref">
+RFC4627
+</a>
+</cite>
+].
+</p>
+<p>
+A
+<a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">
+JSON-LD
+document
+</a>
+<em title="must" class="rfc2119">
+must
+</em>
+be
+a
+single
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>
+or
+a
+JSON
+<a href="#dfn-array" title="array" class="tref internalDFN">
+array
+</a>
+containing
+a
+set
+of
+one
+or
+more
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+objects
+</a>.
+</p>
+<section rel="bibo:chapter" resource="#grammar-node-object" typeof="bibo:Chapter" id="grammar-node-object">
+<h3>
+<span class="secno">
+B.1
+</span>
+Node
+Object
+</h3>
+<p>
+A
+<dfn id="dfn-node-object" title="node-object">
+node
+object
+</dfn>
+represents
+zero
+or
+more
+properties
+of
+a
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>
+in
+the
+<a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">
+JSON-LD
+graph
+</a>
+serialized
+by
+the
+<a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">
+JSON-LD
+document
+</a>.
+A
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+is
+a
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>
+if
+it
+exists
+outside
+of
+a
+JSON-LD
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>
+and:
+</p>
+<ul>
+<li>
+it
+does
+not
+contain
+the
+<code>
+@value
+</code>,
+<code>
+@list
+</code>,
+or
+<code>
+@set
+</code>
+keywords,
+and
+</li>
+<li>
+it
+is
+not
+the
+top-most
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+in
+the
+JSON-LD
+document
+consisting
+of
+no
+other
+members
+than
+<code>
+@graph
+</code>
+and
+<code>
+@context
+</code>.
+</li>
+</ul>
+<p>
+The
+<a href="#dfn-property" title="property" class="tref internalDFN">
+properties
+</a>
+of
+a
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>
+in
+a
+<a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">
+JSON-LD
+graph
+</a>
+may
+be
+spread
+among
+different
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+objects
+</a>
+within
+a
+document.
+When
+that
+happens,
+the
+keys
+of
+the
+different
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+objects
+</a>
+are
+merged
+to
+create
+the
+properties
+of
+the
+resulting
+<a href="#dfn-node" title="node" class="tref internalDFN">
+node
+</a>.
+</p>
+<p>
+A
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>
+<em title="must" class="rfc2119">
+must
+</em>
+be
+a
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>.
+All
+keys
+which
+are
+not
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>,
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+IRIs
+</a>,
+<a href="#dfn-term" title="term" class="tref internalDFN">
+terms
+</a>
+valid
+in
+the
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>,
+or
+one
+of
+the
+following
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keywords
+</a>
+<em title="must" class="rfc2119">
+must
+</em>
+be
+ignored
+when
+processed:
+</p>
+<ul>
+<li>
+<code>
+@context
+</code>,
+</li>
+<li>
+<code>
+@graph
+</code>,
+</li>
+<li>
+<code>
+@id
+</code>,
+</li>
+<li>
+<code>
+@type
+</code>,
+or
+</li>
+<li>
+<code>
+@index
+</code>
+</li>
+</ul>
+<p>
+If
+the
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>
+contains
+the
+<code>
+@context
+</code>
+key,
+its
+value
+<em title="must" class="rfc2119">
+must
+</em>
+be
+one
+of
+the
+following:
+</p>
+<ul>
+<li>
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>,
+</li>
+<li>
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+</li>
+<li>
+a
+<a href="#dfn-context-definition" title="context-definition" class="tref internalDFN">
+context
+definition
+</a>,
+or
+</li>
+<li>
+an
+<a href="#dfn-array" title="array" class="tref internalDFN">
+array
+</a>
+composed
+of
+any
+number
+of
+the
+previous
+two
+expressions.
+</li>
+</ul>
+<p>
+If
+the
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>
+contains
+the
+<code>
+@id
+</code>
+key,
+its
+value
+<em title="must" class="rfc2119">
+must
+</em>
+be
+an
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+a
+<a href="#dfn-relative-iri" title="relative-iri" class="tref internalDFN">
+relative
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+or
+a
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+(including
+<a href="#dfn-blank-node-identifier" title="blank-node-identifier" class="tref internalDFN">
+blank
+node
+identifiers
+</a>
+).
+See
+<a class="sec-ref" href="#node-identifiers">
+<span class="secno">
+5.3
+</span>
+<span class="sec-title">
+Node
+Identifiers
+</span>
+</a>,
+<a class="sec-ref" href="#compact-iris">
+<span class="secno">
+6.1
+</span>
+<span class="sec-title">
+Compact
+IRIs
+</span>
+</a>,
+and
+<a class="sec-ref" href="#identifying-blank-nodes">
+<span class="secno">
+<del class="diff-old">6.12
+</del>
+<ins class="diff-chg">6.13
+</ins>
+</span>
+<span class="sec-title">
+Identifying
+Blank
+Nodes
+</span>
+</a>
+for
+further
+discussion
+on
+<code>
+@id
+</code>
+values.
+</p>
+<p>
+If
+the
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>
+contains
+the
+<code>
+@type
+</code>
+key,
+its
+value
+<em title="must" class="rfc2119">
+must
+</em>
+be
+either
+an
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+a
+<a href="#dfn-relative-iri" title="relative-iri" class="tref internalDFN">
+relative
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+a
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+(including
+<a href="#dfn-blank-node-identifier" title="blank-node-identifier" class="tref internalDFN">
+blank
+node
+identifiers
+</a>
+),
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+defined
+in
+the
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>
+expanding
+into
+an
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+or
+an
+<a href="#dfn-array" title="array" class="tref internalDFN">
+array
+</a>
+of
+any
+of
+these.
+See
+<a class="sec-ref" href="#specifying-the-type">
+<span class="secno">
+5.4
+</span>
+<span class="sec-title">
+Specifying
+the
+Type
+</span>
+</a>
+for
+further
+discussion
+on
+<code>
+@type
+</code>
+values.
+</p>
+<p>
+If
+the
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>
+contains
+the
+<code>
+@graph
+</code>
+key,
+its
+value
+<em title="must" class="rfc2119">
+must
+</em>
+be
+a
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>
+or
+an
+<a href="#dfn-array" title="array" class="tref internalDFN">
+array
+</a>
+of
+zero
+or
+more
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+objects
+</a>.
+If
+the
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>
+contains
+an
+<code>
+@id
+</code>
+keyword,
+its
+value
+is
+used
+as
+the
+label
+of
+a
+named
+graph.
+See
+<a class="sec-ref" href="#named-graphs">
+<span class="secno">
+<del class="diff-old">6.11
+</del>
+<ins class="diff-chg">6.12
+</ins>
+</span>
+<span class="sec-title">
+Named
+Graphs
+</span>
+</a>
+for
+further
+discussion
+on
+<code>
+@graph
+</code>
+values.
+As
+a
+special
+case,
+if
+a
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+contains
+no
+keys
+other
+than
+<code>
+@graph
+</code>
+and
+<code>
+@context
+</code>,
+and
+the
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+is
+the
+root
+of
+the
+JSON-LD
+document,
+the
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+is
+not
+treated
+as
+a
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>
+;
+this
+is
+used
+as
+a
+way
+of
+defining
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+definitions
+</a>
+that
+may
+not
+form
+a
+connected
+graph.
+This
+allows
+a
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>
+to
+be
+defined
+which
+is
+shared
+by
+all
+of
+the
+constituent
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+objects
+</a>.
+</p>
+<p>
+If
+the
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>
+contains
+the
+<code>
+@index
+</code>
+key,
+its
+value
+<em title="must" class="rfc2119">
+must
+</em>
+be
+a
+<a href="#dfn-string" title="string" class="tref internalDFN">
+string
+</a>.
+See
+section
+<a class="sec-ref" href="#data-indexing">
+<span class="secno">
+<del class="diff-old">6.16
+</del>
+<ins class="diff-chg">6.17
+</ins>
+</span>
+<span class="sec-title">
+Data
+Indexing
+</span>
+</a>
+for
+further
+discussion
+on
+<code>
+@index
+</code>
+values.
+</p>
+<p>
+Keys
+in
+a
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>
+that
+are
+not
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keywords
+</a>
+<em title="must" class="rfc2119">
+must
+</em>
+expand
+to
+an
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+using
+the
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>.
+The
+values
+associated
+with
+these
+keys
+<em title="must" class="rfc2119">
+must
+</em>
+be
+one
+of
+the
+following:
+</p>
+<ul>
+<li>
+<a href="#dfn-string" title="string" class="tref internalDFN">
+string
+</a>,
+</li>
+<li>
+<a href="#dfn-number" title="number" class="tref internalDFN">
+number
+</a>,
+</li>
+<li>
+<a href="#dfn-true" title="true" class="tref internalDFN">
+true
+</a>,
+</li>
+<li>
+<a href="#dfn-false" title="false" class="tref internalDFN">
+false
+</a>,
+</li>
+<li>
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>,
+</li>
+<li>
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>,
+</li>
+<li>
+<a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">
+expanded
+value
+</a>,
+</li>
+<li>
+<a href="#dfn-list" title="list" class="tref internalDFN">
+list
+</a>
+or
+<a href="#dfn-set" title="set" class="tref internalDFN">
+set
+</a>,
+</li>
+<li>
+an
+<a href="#dfn-array" title="array" class="tref internalDFN">
+array
+</a>
+of
+zero
+or
+more
+of
+the
+possibilities
+above,
+</li>
+<li>
+a
+<a href="#dfn-language-map" title="language-map" class="tref internalDFN">
+language
+map
+</a>,
+or
+</li>
+<li>
+an
+<a href="#dfn-index-map" title="index-map" class="tref internalDFN">
+index
+map
+</a>
+</li>
+</ul>
+</section>
+<section rel="bibo:chapter" resource="#grammar-term-reference" typeof="bibo:Chapter" id="grammar-term-reference">
+<h3>
+<span class="secno">
+B.2
+</span>
+Term
+</h3>
+<p>
+A
+<dfn id="dfn-term" title="term">
+term
+</dfn>
+is
+a
+short-hand
+<a href="#dfn-string" title="string" class="tref internalDFN">
+string
+</a>
+that
+expands
+to
+an
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+or
+a
+<a href="#dfn-blank-node-identifier" title="blank-node-identifier" class="tref internalDFN">
+blank
+node
+identifier
+</a>.
+</p>
+<p>
+A
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+<em title="must not" class="rfc2119">
+must
+not
+</em>
+equal
+any
+of
+the
+JSON-LD
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keywords
+</a>.
+</p>
+<p>
+To
+avoid
+forward-compatibility
+issues,
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+<em title="should not" class="rfc2119">
+should
+not
+</em>
+start
+with
+an
+<code>
+@
+</code>
+character
+as
+future
+versions
+of
+JSON-LD
+may
+introduce
+additional
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keywords
+</a>.
+Furthermore,
+the
+use
+of
+empty
+terms
+(
+<code>
+""
+</code>
+)
+is
+discouraged
+as
+not
+all
+programming
+languages
+are
+able
+to
+handle
+empty
+property
+names.
+</p>
+<p>
+See
+<a class="sec-ref" href="#the-context">
+<span class="secno">
+5.1
+</span>
+<span class="sec-title">
+The
+Context
+</span>
+</a>
+and
+<a class="sec-ref" href="#iris">
+<span class="secno">
+5.2
+</span>
+<span class="sec-title">
+IRIs
+</span>
+</a>
+for
+further
+discussion
+on
+mapping
+<a href="#dfn-term" title="term" class="tref internalDFN">
+terms
+</a>
+to
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>.
+</p>
+</section>
+<section rel="bibo:chapter" resource="#grammar-language-map" typeof="bibo:Chapter" id="grammar-language-map">
+<h3>
+<span class="secno">
+B.3
+</span>
+Language
+Map
+</h3>
+<p>
+A
+<dfn id="dfn-language-map" title="language-map">
+language
+map
+</dfn>
+is
+used
+to
+associate
+a
+language
+with
+a
+value
+in
+a
+way
+that
+allows
+easy
+programmatic
+access.
+A
+<a href="#dfn-language-map" title="language-map" class="tref internalDFN">
+language
+map
+</a>
+may
+be
+used
+as
+a
+term
+value
+within
+a
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>
+if
+the
+term
+is
+defined
+with
+<code>
+@container
+</code>
+set
+to
+<code>
+@language
+</code>.
+The
+keys
+of
+a
+<a href="#dfn-language-map" title="language-map" class="tref internalDFN">
+language
+map
+</a>
+<em title="must" class="rfc2119">
+must
+</em>
+be
+lowercase
+[
+<cite>
+<a href="#bib-BCP47" class="bibref">
+BCP47
+</a>
+</cite>
+]
+<a href="#dfn-string" title="string" class="tref internalDFN">
+strings
+</a>
+with
+an
+associated
+value
+that
+is
+any
+of
+the
+following
+types:
+</p>
+<ul>
+<li>
+<a href="#dfn-string" title="string" class="tref internalDFN">
+string
+</a>,
+or
+</li>
+<li>
+an
+<a href="#dfn-array" title="array" class="tref internalDFN">
+array
+</a>
+of
+zero
+or
+more
+strings
+</li>
+</ul>
+<p>
+See
+<a href="#language-tagged-strings">
+</a>
+for
+further
+discussion
+on
+language
+maps.
+</p>
+</section>
+<section rel="bibo:chapter" resource="#grammar-index-map" typeof="bibo:Chapter" id="grammar-index-map">
+<h3>
+<span class="secno">
+B.4
+</span>
+Index
+Map
+</h3>
+<p>
+An
+<dfn id="dfn-index-map" title="index-map">
+index
+map
+</dfn>
+allows
+keys
+that
+have
+no
+semantic
+meaning,
+but
+should
+be
+preserved
+regardless,
+to
+be
+used
+in
+JSON-LD
+documents.
+An
+<a href="#dfn-index-map" title="index-map" class="tref internalDFN">
+index
+map
+</a>
+may
+be
+used
+as
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+value
+within
+a
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>
+if
+the
+term
+is
+defined
+with
+<code>
+@container
+</code>
+set
+to
+<code>
+@index
+</code>.
+The
+values
+of
+the
+members
+of
+an
+<a href="#dfn-index-map" title="index-map" class="tref internalDFN">
+index
+map
+</a>
+<em title="must" class="rfc2119">
+must
+</em>
+be
+one
+of
+the
+following
+types:
+</p>
+<ul>
+<li>
+<a href="#dfn-string" title="string" class="tref internalDFN">
+string
+</a>,
+</li>
+<li>
+<a href="#dfn-number" title="number" class="tref internalDFN">
+number
+</a>,
+</li>
+<li>
+<a href="#dfn-true" title="true" class="tref internalDFN">
+true
+</a>,
+</li>
+<li>
+<a href="#dfn-false" title="false" class="tref internalDFN">
+false
+</a>,
+</li>
+<li>
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>,
+</li>
+<li>
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>,
+</li>
+<li>
+<a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">
+expanded
+value
+</a>,
+</li>
+<li>
+an
+<a href="#dfn-array" title="array" class="tref internalDFN">
+array
+</a>
+of
+zero
+or
+more
+of
+the
+above
+possibilities
+</li>
+</ul>
+<p>
+See
+<a class="sec-ref" href="#data-indexing">
+<span class="secno">
+<del class="diff-old">6.16
+</del>
+<ins class="diff-chg">6.17
+</ins>
+</span>
+<span class="sec-title">
+Data
+Indexing
+</span>
+</a>
+for
+further
+information
+on
+this
+topic.
+</p>
+</section>
+<section rel="bibo:chapter" resource="#grammar-expanded-values" typeof="bibo:Chapter" id="grammar-expanded-values">
+<h3>
+<span class="secno">
+B.5
+</span>
+Expanded
+Values
+</h3>
+<p>
+An
+<dfn id="dfn-expanded-value" title="expanded-value">
+expanded
+value
+</dfn>
+is
+used
+to
+explicitly
+associate
+a
+type
+or
+a
+language
+with
+a
+value
+to
+create
+a
+<a href="#dfn-typed-value" title="typed-value" class="tref internalDFN">
+typed
+value
+</a>
+or
+a
+<a href="#dfn-language-tagged-string" title="language-tagged-string" class="tref internalDFN">
+language-tagged
+string
+</a>.
+</p>
+<p>
+An
+<a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">
+expanded
+value
+</a>
+<em title="must" class="rfc2119">
+must
+</em>
+be
+a
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+containing
+the
+<code>
+@value
+</code>
+key.
+It
+<em title="may" class="rfc2119">
+may
+</em>
+also
+contain
+a
+<code>
+@type
+</code>,
+a
+<code>
+@language
+</code>,
+or
+an
+<code>
+@index
+</code>
+key
+but
+<em title="must not" class="rfc2119">
+must
+not
+</em>
+contain
+both
+a
+<code>
+@type
+</code>
+and
+a
+<code>
+@language
+</code>
+key
+at
+the
+same
+time.
+An
+<a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">
+expanded
+value
+</a>
+<em title="must not" class="rfc2119">
+must
+not
+</em>
+contain
+keys
+other
+than
+<code>
+@value
+</code>,
+<code>
+@type
+</code>,
+<code>
+@language
+</code>,
+and
+<code>
+@index
+</code>.
+An
+<a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">
+expanded
+value
+</a>
+that
+contains
+a
+<code>
+@type
+</code>
+key
+is
+called
+an
+<dfn id="dfn-expanded-typed-value" title="expanded-typed-value">
+expanded
+typed
+value
+</dfn>.
+An
+<a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">
+expanded
+value
+</a>
+that
+contains
+a
+<code>
+@language
+</code>
+key
+is
+called
+an
+<dfn id="dfn-expanded-language-tagged-string" title="expanded-language-tagged-string">
+expanded
+language-tagged
+string
+</dfn>.
+</p>
+<p>
+The
+value
+associated
+with
+the
+<code>
+@value
+</code>
+key
+<em title="must" class="rfc2119">
+must
+</em>
+be
+either
+a
+<a href="#dfn-string" title="string" class="tref internalDFN">
+string
+</a>,
+<a href="#dfn-number" title="number" class="tref internalDFN">
+number
+</a>,
+<a href="#dfn-true" title="true" class="tref internalDFN">
+true
+</a>,
+<a href="#dfn-false" title="false" class="tref internalDFN">
+false
+</a>
+or
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>.
+</p>
+<p>
+The
+value
+associated
+with
+the
+<code>
+@type
+</code>
+key
+<em title="must" class="rfc2119">
+must
+</em>
+be
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>,
+a
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+an
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+a
+<a href="#dfn-relative-iri" title="relative-iri" class="tref internalDFN">
+relative
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+or
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>.
+</p>
+<p>
+The
+value
+associated
+with
+the
+<code>
+@language
+</code>
+key
+<em title="must" class="rfc2119">
+must
+</em>
+have
+the
+lexical
+form
+described
+in
+[
+<cite>
+<a href="#bib-BCP47" class="bibref">
+BCP47
+</a>
+</cite>
+],
+or
+be
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>.
+</p>
+<p>
+The
+value
+associated
+with
+the
+<code>
+@index
+</code>
+key
+<em title="must" class="rfc2119">
+must
+</em>
+be
+a
+<a href="#dfn-string" title="string" class="tref internalDFN">
+string
+</a>.
+</p>
+<p>
+See
+<a class="sec-ref" href="#typed-values">
+<span class="secno">
+6.2
+</span>
+<span class="sec-title">
+Typed
+Values
+</span>
+</a>
+and
+<a href="#language-tagged-strings">
+</a>
+for
+more
+information
+on
+<a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">
+expanded
+values
+</a>.
+</p>
+</section>
+<section rel="bibo:chapter" resource="#grammar-set-list" typeof="bibo:Chapter" id="grammar-set-list">
+<h3>
+<span class="secno">
+B.6
+</span>
+List
+and
+Set
+Values
+</h3>
+<p>
+A
+<a href="#dfn-list" title="list" class="tref internalDFN">
+list
+</a>
+represents
+an
+<em>
+ordered
+</em>
+set
+of
+values.
+A
+<dfn id="dfn-set" title="set">
+set
+</dfn>
+represents
+an
+<em>
+unordered
+</em>
+set
+of
+values.
+Unless
+otherwise
+specified,
+<a href="#dfn-array" title="array" class="tref internalDFN">
+arrays
+</a>
+are
+unordered
+in
+JSON-LD.
+As
+such,
+the
+<code>
+@set
+</code>
+keyword,
+when
+used
+in
+the
+body
+of
+a
+JSON-LD
+document,
+represents
+just
+syntactic
+sugar
+which
+is
+optimized
+away
+when
+processing
+the
+document.
+However,
+it
+is
+very
+helpful
+when
+used
+within
+the
+context
+of
+a
+document.
+Values
+of
+terms
+associated
+with
+a
+<code>
+@set
+</code>
+or
+<code>
+@list
+</code>
+container
+will
+always
+be
+represented
+in
+the
+form
+of
+an
+array
+when
+a
+document
+is
+processed
+-
+even
+if
+there
+is
+just
+a
+single
+value
+that
+would
+otherwise
+be
+optimized
+to
+a
+non-array
+form
+in
+<a href="#compact-document-form">
+compact
+document
+form
+</a>.
+This
+simplifies
+post-processing
+of
+the
+data
+as
+the
+data
+is
+always
+in
+array
+form.
+</p>
+<p>
+A
+<a href="#dfn-list" title="list" class="tref internalDFN">
+list
+</a>
+<em title="must" class="rfc2119">
+must
+</em>
+be
+a
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+that
+contains
+no
+other
+keys
+than
+<code>
+@list
+</code>,
+<code>
+@context
+</code>,
+and
+<code>
+@index
+</code>.
+</p>
+<p>
+A
+<a href="#dfn-set" title="set" class="tref internalDFN">
+set
+</a>
+<em title="must" class="rfc2119">
+must
+</em>
+be
+a
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+that
+that
+contains
+no
+other
+keys
+than
+<code>
+@set
+</code>,
+<code>
+@context
+</code>,
+and
+<code>
+@index
+</code>.
+Please
+note
+that
+the
+<code>
+@index
+</code>
+key
+will
+be
+ignored,
+and
+thus
+be
+dropped,
+when
+being
+processed.
+</p>
+<p>
+In
+both
+cases,
+the
+value
+associated
+with
+the
+keys
+<code>
+@list
+</code>
+and
+<code>
+@set
+</code>
+<em title="must" class="rfc2119">
+must
+</em>
+be
+an
+<a href="#dfn-array" title="array" class="tref internalDFN">
+array
+</a>
+of
+any
+of
+the
+following:
+</p>
+<ul>
+<li>
+<a href="#dfn-string" title="string" class="tref internalDFN">
+string
+</a>,
+</li>
+<li>
+<a href="#dfn-number" title="number" class="tref internalDFN">
+number
+</a>,
+</li>
+<li>
+<a href="#dfn-true" title="true" class="tref internalDFN">
+true
+</a>,
+</li>
+<li>
+<a href="#dfn-false" title="false" class="tref internalDFN">
+false
+</a>,
+</li>
+<li>
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>,
+</li>
+<li>
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>,
+or
+</li>
+<li>
+<a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">
+expanded
+value
+</a>
+</li>
+</ul>
+<p>
+See
+<a class="sec-ref" href="#sets-and-lists">
+<span class="secno">
+<del class="diff-old">6.9
+</del>
+<ins class="diff-chg">6.10
+</ins>
+</span>
+<span class="sec-title">
+Sets
+and
+Lists
+</span>
+</a>
+for
+further
+discussion
+on
+List
+and
+Set
+Values.
+</p>
+</section>
+<section rel="bibo:chapter" resource="#grammar-context" typeof="bibo:Chapter" id="grammar-context">
+<h3>
+<span class="secno">
+B.7
+</span>
+Context
+Definition
+</h3>
+<p>
+A
+<dfn id="dfn-context-definition" title="context-definition">
+context
+definition
+</dfn>
+defines
+a
+<a href="#dfn-local-context" title="local-context" class="tref internalDFN">
+local
+context
+</a>
+in
+a
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>.
+</p>
+<p>
+A
+<a href="#dfn-context-definition" title="context-definition" class="tref internalDFN">
+context
+definition
+</a>
+<em title="must" class="rfc2119">
+must
+</em>
+be
+a
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+containing
+one
+or
+more
+key-value
+pairs.
+Keys
+<em title="must" class="rfc2119">
+must
+</em>
+either
+be
+<a href="#dfn-term" title="term" class="tref internalDFN">
+terms
+</a>
+or
+<code>
+@language
+</code>
+or
+<code>
+@vocab
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keywords
+</a>.
+</p>
+<p>
+If
+the
+<a href="#dfn-context-definition" title="context-definition" class="tref internalDFN">
+context
+definition
+</a>
+has
+a
+<code>
+@language
+</code>
+key,
+its
+value
+<em title="must" class="rfc2119">
+must
+</em>
+have
+the
+lexical
+form
+described
+in
+[
+<cite>
+<a href="#bib-BCP47" class="bibref">
+BCP47
+</a>
+</cite>
+]
+or
+be
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>.
+</p>
+<p>
+If
+the
+<a href="#dfn-context-definition" title="context-definition" class="tref internalDFN">
+context
+definition
+</a>
+has
+a
+<code>
+@vocab
+</code>
+key,
+its
+value
+<em title="must" class="rfc2119">
+must
+</em>
+have
+the
+lexical
+form
+of
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+or
+be
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>.
+</p>
+<p>
+<a href="#dfn-term" title="term" class="tref internalDFN">
+Term
+</a>
+values
+<em title="must" class="rfc2119">
+must
+</em>
+be
+either
+a
+<a href="#dfn-string" title="string" class="tref internalDFN">
+string
+</a>,
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>,
+or
+an
+<a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">
+expanded
+term
+definition
+</a>.
+</p>
+<p>
+An
+<a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">
+expanded
+term
+definition
+</a>
+is
+used
+to
+describe
+the
+mapping
+between
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+and
+its
+expanded
+identifier,
+as
+well
+as
+other
+properties
+of
+the
+value
+associated
+with
+the
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+when
+it
+is
+used
+as
+key
+in
+a
+<a href="#dfn-node-object" title="node-object" class="tref internalDFN">
+node
+object
+</a>.
+</p>
+<p>
+An
+<a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">
+expanded
+term
+definition
+</a>
+<em title="should" class="rfc2119">
+should
+</em>
+be
+a
+<a href="#dfn-json-object" title="json-object" class="tref internalDFN">
+JSON
+object
+</a>
+composed
+of
+zero
+or
+more
+keys
+from
+<code>
+@id
+</code>,
+<code>
+@type
+</code>,
+<code>
+@language
+</code>
+or
+<code>
+@container
+</code>.
+An
+<a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">
+expanded
+term
+definition
+</a>
+<em title="should not" class="rfc2119">
+should
+not
+</em>
+contain
+any
+other
+keys.
+</p>
+<p>
+If
+the
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+definition
+is
+not
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>,
+a
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+or
+an
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>
+and
+the
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>
+does
+not
+have
+an
+<code>
+@vocab
+</code>
+mapping,
+the
+<a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">
+expanded
+term
+definition
+</a>
+<em title="must" class="rfc2119">
+must
+</em>
+include
+the
+<code>
+@id
+</code>
+key.
+</p>
+<p>
+If
+the
+<a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">
+expanded
+term
+definition
+</a>
+contains
+the
+<code>
+@id
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>,
+its
+value
+<em title="must" class="rfc2119">
+must
+</em>
+be
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>,
+an
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+a
+<a href="#dfn-blank-node-identifier" title="blank-node-identifier" class="tref internalDFN">
+blank
+node
+identifier
+</a>,
+a
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+defined
+in
+the
+defining
+<a href="#dfn-context-definition" title="context-definition" class="tref internalDFN">
+context
+definition
+</a>
+or
+the
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>,
+or
+an
+<a href="#dfn-array" title="array" class="tref internalDFN">
+array
+</a>
+composed
+of
+any
+of
+the
+previous
+allowed
+values
+except
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>.
+</p>
+<p>
+If
+the
+<a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">
+expanded
+term
+definition
+</a>
+contains
+the
+<code>
+@type
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>,
+its
+value
+<em title="must" class="rfc2119">
+must
+</em>
+be
+an
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">
+absolute
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+a
+<a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">
+compact
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>,
+a
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+defined
+in
+the
+defining
+<a href="#dfn-context-definition" title="context-definition" class="tref internalDFN">
+context
+definition
+</a>
+or
+the
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>,
+<a href="#dfn-null" title="null" class="tref internalDFN">
+<ins class="diff-new">null
+</ins></a>,
+or
+the
+<ins class="diff-new">one
+of
+the
+</ins><a href="#dfn-keyword" title="keyword" class="tref internalDFN"><ins class="diff-new">
+keywords
+</ins></a>
+<code>
+@id
+</code>
+<del class="diff-old">keyword
+.
+</del>
+<ins class="diff-chg">or
+</ins><code><ins class="diff-chg">
+@vocab
+</ins></code>.
+</p>
+<p>
+If
+the
+<a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">
+expanded
+term
+definition
+</a>
+contains
+the
+<code>
+@language
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>,
+its
+value
+<em title="must" class="rfc2119">
+must
+</em>
+have
+the
+lexical
+form
+described
+in
+[
+<cite>
+<a href="#bib-BCP47" class="bibref">
+BCP47
+</a>
+</cite>
+]
+or
+be
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>.
+</p>
+<p>
+If
+the
+<a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">
+expanded
+term
+definition
+</a>
+contains
+the
+<code>
+@container
+</code>
+<a href="#dfn-keyword" title="keyword" class="tref internalDFN">
+keyword
+</a>,
+its
+value
+<em title="must" class="rfc2119">
+must
+</em>
+be
+either
+<code>
+@list
+</code>,
+<code>
+@set
+</code>,
+<code>
+@language
+</code>,
+<code>
+@index
+</code>,
+or
+be
+<a href="#dfn-null" title="null" class="tref internalDFN">
+null
+</a>.
+If
+the
+value
+is
+<code>
+@language
+</code>,
+when
+the
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+is
+used
+outside
+of
+the
+<code>
+@context
+</code>,
+the
+associated
+value
+<em title="must" class="rfc2119">
+must
+</em>
+be
+a
+<a href="#dfn-language-map" title="language-map" class="tref internalDFN">
+language
+map
+</a>.
+If
+the
+value
+is
+<code>
+@index
+</code>,
+when
+the
+<a href="#dfn-term" title="term" class="tref internalDFN">
+term
+</a>
+is
+used
+outside
+of
+the
+<code>
+@context
+</code>,
+the
+associated
+value
+<em title="must" class="rfc2119">
+must
+</em>
+be
+an
+<a href="#dfn-index-map" title="index-map" class="tref internalDFN">
+index
+map
+</a>.
+</p>
+<p>
+<a href="#dfn-term" title="term" class="tref internalDFN">
+Terms
+</a>
+<em title="must not" class="rfc2119">
+must
+not
+</em>
+be
+used
+in
+a
+circular
+manner.
+That
+is,
+the
+definition
+of
+a
+term
+cannot
+depend
+on
+the
+definition
+of
+another
+term
+if
+that
+other
+term
+also
+depends
+on
+the
+first
+term.
+</p>
+<p>
+See
+<a class="sec-ref" href="#the-context">
+<span class="secno">
+5.1
+</span>
+<span class="sec-title">
+The
+Context
+</span>
+</a>
+for
+further
+discussion
+on
+contexts.
+</p>
+</section>
+</section>
+<section id="relationship-to-rdf" class="appendix normative">
+<h2>
+<span class="secno">
+C.
+</span>
+Relationship
+to
+RDF
+</h2>
+<p>
+The
+RDF
+data
+model,
+as
+outlined
+in
+[
+<cite>
+<a href="#bib-RDF-CONCEPTS" class="bibref">
+RDF-CONCEPTS
+</a>
+</cite>
+],
+is
+an
+abstract
+syntax
+for
+representing
+a
+directed
+graph
+of
+information.
+It
+is
+a
+subset
+of
+<a href="#dfn-json-ld-data-model" title="json-ld-data-model" class="tref internalDFN">
+JSON-LD's
+data
+model
+</a>
+with
+a
+few
+additional
+constraints.
+The
+differences
+between
+the
+two
+data
+models
+are:
+</p>
+<ul>
+<li>
+In
+JSON-LD
+<a href="#dfn-graph-name" title="graph-name" class="tref internalDFN">
+graph
+names
+</a>
+can
+be
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>
+or
+<a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">
+blank
+nodes
+</a>
+whereas
+in
+RDF
+graph
+names
+have
+to
+be
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>.
+</li>
+<li>
+In
+JSON-LD
+<a href="#dfn-property" title="property" class="tref internalDFN">
+properties
+</a>
+can
+be
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>
+or
+<a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">
+blank
+nodes
+</a>
+whereas
+in
+RDF
+properties
+(predicates)
+have
+to
+be
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+IRIs
+</a>.
+</li>
+<li>
+In
+JSON-LD
+lists
+are
+part
+of
+the
+data
+model
+whereas
+in
+RDF
+they
+are
+part
+of
+a
+vocabulary,
+namely
+[
+<cite>
+<a href="#bib-RDF-SCHEMA" class="bibref">
+RDF-SCHEMA
+</a>
+</cite>
+].
+</li>
+<li>
+RDF
+values
+are
+either
+typed
+<em>
+literals
+</em>
+(
+<a href="#dfn-typed-value" title="typed-value" class="tref internalDFN">
+typed
+values
+</a>
+)
+or
+<em>
+language-tagged
+strings
+</em>
+(
+<a href="#dfn-language-tagged-string" title="language-tagged-string" class="tref internalDFN">
+language-tagged
+strings
+</a>
+)
+whereas
+JSON-LD
+also
+supports
+JSON's
+native
+data
+types,
+i.e.,
+<a href="#dfn-number" title="number" class="tref internalDFN">
+number
+</a>,
+<a href="#dfn-string" title="string" class="tref internalDFN">
+strings
+</a>,
+and
+the
+boolean
+values
+<a href="#dfn-true" title="true" class="tref internalDFN">
+true
+</a>
+and
+<a href="#dfn-false" title="false" class="tref internalDFN">
+false
+</a>.
+The
+JSON-LD
+Algorithms
+and
+API
+specification
+[
+<cite>
+<a href="#bib-JSON-LD-API" class="bibref">
+JSON-LD-API
+</a>
+</cite>
+]
+defines
+the
+conversion
+rules
+between
+JSON's
+native
+data
+types
+and
+RDF's
+counterparts
+to
+allow
+full
+round-tripping.
+</li>
+</ul>
+<p>
+Summarized
+these
+differences
+mean
+that
+JSON-LD
+is
+capable
+of
+serializing
+any
+RDF
+graph
+or
+dataset
+and
+most,
+but
+not
+all,
+JSON-LD
+documents
+can
+be
+transformed
+to
+RDF.
+A
+complete
+description
+of
+the
+algorithms
+to
+convert
+from
+RDF
+to
+JSON-LD
+and
+from
+JSON-LD
+to
+RDF
+is
+included
+in
+the
+JSON-LD
+Algorithms
+and
+API
+specification
+[
+<cite>
+<a href="#bib-JSON-LD-API" class="bibref">
+JSON-LD-API
+</a>
+</cite>
+].
+</p>
+<p>
+Even
+though
+JSON-LD
+serializes
+RDF
+datasets,
+it
+can
+also
+be
+used
+as
+a
+RDF
+graph
+source.
+In
+that
+case,
+a
+consumer
+<em title="must" class="rfc2119">
+must
+</em>
+only
+use
+the
+default
+graph
+and
+ignore
+all
+named
+graphs.
+This
+allows
+servers
+to
+expose
+data
+in,
+e.g.,
+both
+Turtle
+and
+JSON-LD
+using
+content
+negotiation.
+</p>
+<div class="note">
+<div class="note-title">
+<span>
+Note
+</span>
+</div>
+<p class="">
+Publishers
+supporting
+both
+dataset
+and
+graph
+syntaxes
+have
+to
+ensure
+that
+the
+primary
+data
+is
+stored
+in
+the
+default
+graph
+to
+enable
+consumers
+that
+do
+not
+support
+datasets
+to
+process
+the
+information.
+</p>
+</div>
+</section>
+<section id="relationship-to-other-linked-data-formats" class="appendix informative">
+<h2>
+<span class="secno">
+D.
+</span>
+Relationship
+to
+Other
+Linked
+Data
+Formats
+</h2>
+<p>
+<em>
+This
+section
+is
+non-normative.
+</em>
+</p>
+<p>
+The
+JSON-LD
+markup
+examples
+below
+demonstrate
+how
+JSON-LD
+can
+be
+used
+to
+express
+semantic
+data
+marked
+up
+in
+other
+linked
+data
+formats
+such
+as
+Turtle,
+RDFa,
+Microformats,
+and
+Microdata.
+These
+sections
+are
+merely
+provided
+as
+evidence
+that
+JSON-LD
+is
+very
+flexible
+in
+what
+it
+can
+express
+across
+different
+<a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">
+Linked
+Data
+</a>
+approaches.
+</p>
+<section id="turtle">
+<h3>
+<span class="secno">
+D.1
+</span>
+Turtle
+</h3>
+<p>
+<em>
+This
+section
+is
+non-normative.
+</em>
+</p>
+<p>
+The
+following
+are
+examples
+of
+converting
+RDF
+expressed
+in
+<ins class="diff-new">Turtle
+</ins>
+[
+<cite>
+<a href="#bib-TURTLE-TR" class="bibref">
+TURTLE-TR
+</a>
+</cite>
+]
+into
+JSON-LD.
+</p>
+<section id="prefix-definitions">
+<h4>
+<span class="secno">
+D.1.1
+</span>
+Prefix
+definitions
+</h4>
+<p>
+<em>
+This
+section
+is
+non-normative.
+</em>
+</p>
+<p>
+The
+JSON-LD
+context
+has
+direct
+equivalents
+for
+the
+Turtle
+<code>
+@prefix
+</code>
+declaration:
+</p>
+<del class="diff-old">@prefix foaf: <http://xmlns.com/foaf/0.1/> .
+<http://manu.sporny.org/i/public> a foaf:Person;
+ foaf:name "Manu Sporny";
+</del>
+<div class="example"><div class="example-title"><span>Example 57</span>: A set of statements serialized in Turtle</div><pre class="example">@prefix foaf: <http://xmlns.com/foaf/0.1/> .
+<ins class="diff-chg">
+<http://manu.sporny.org/i/public> a foaf:Person;
+ foaf:name "Manu Sporny";
+</ins>
+foaf:homepage
+<http://manu.sporny.org/>
+.
+</pre>
+</div>
+<del class="diff-old">{
+ "@context":
+ {
+ "foaf": "http://xmlns.com/foaf/0.1/"
+ },
+ "@id": "http://manu.sporny.org/i/public",
+ "@type": "foaf:Person",
+ "foaf:name": "Manu Sporny",
+ "foaf:homepage": { "@id": "http://manu.sporny.org/" }
+</del>
+<div class="example"><div class="example-title"><span>Example 58</span>: The same set of statements serialized in JSON-LD</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+ "foaf": "http://xmlns.com/foaf/0.1/"
+ },
+ "@id": "http://manu.sporny.org/i/public",
+ "@type": "foaf:Person",
+ "foaf:name": "Manu Sporny",
+ "foaf:homepage": { "@id": "http://manu.sporny.org/" }
+</ins>
+}
+</pre>
+</div>
+<div class="note">
+<div class="note-title">
+<span>
+Note
+</span>
+</div>
+<p class="">
+JSON-LD
+has
+no
+equivalent
+for
+the
+Turtle
+<code>
+@base
+</code>
+declaration,
+but
+can
+use
+a
+prefix
+such
+as
+<code>
+base
+</code>
+to
+encode
+the
+information
+in
+the
+document.
+</p>
+</div>
+</section>
+<section id="embedding-1">
+<h4>
+<span class="secno">
+D.1.2
+</span>
+Embedding
+</h4>
+<p>
+Both
+Turtle
+and
+JSON-LD
+allow
+embedding,
+although
+Turtle
+only
+allows
+embedding
+of
+<a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">
+blank
+nodes
+</a>.
+</p>
+</section>
+<del class="diff-old">@prefix foaf: <http://xmlns.com/foaf/0.1/> .
+<http://manu.sporny.org/i/public>
+ a foaf:Person;
+ foaf:name "Manu Sporny";
+</del>
+<div class="example"><div class="example-title"><span>Example 59</span>: Embedding in Turtle</div><pre class="example">@prefix foaf: <http://xmlns.com/foaf/0.1/> .
+<ins class="diff-chg">
+<http://manu.sporny.org/i/public>
+ a foaf:Person;
+ foaf:name "Manu Sporny";
+</ins>
+foaf:knows
+[
+a
+foaf:Person;
+foaf:name
+"Gregg
+Kellogg"
+]
+.
+</pre>
+</div>
+<del class="diff-old">{
+ "@context":
+ {
+ "foaf": "http://xmlns.com/foaf/0.1/"
+ },
+ "@id": "http://manu.sporny.org/i/public",
+ "@type": "foaf:Person",
+ "foaf:name": "Manu Sporny",
+ "foaf:knows":
+ {
+ "@type": "foaf:Person",
+ "foaf:name": "Gregg Kellogg"
+ }
+</del>
+<div class="example"><div class="example-title"><span>Example 60</span>: Same embedding example in JSON-LD</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+ "foaf": "http://xmlns.com/foaf/0.1/"
+ },
+ "@id": "http://manu.sporny.org/i/public",
+ "@type": "foaf:Person",
+ "foaf:name": "Manu Sporny",
+ "foaf:knows":
+ {
+ "@type": "foaf:Person",
+ "foaf:name": "Gregg Kellogg"
+ }
+</ins>
+}
+</pre>
+</div>
+<section id="lists">
+<h4>
+<span class="secno">
+D.1.3
+</span>
+Lists
+</h4>
+<p>
+Both
+JSON-LD
+and
+Turtle
+can
+represent
+sequential
+lists
+of
+values.
+</p>
+<del class="diff-old">@prefix foaf: <http://xmlns.com/foaf/0.1/> .
+<http://example.org/people#joebob> a foaf:Person;
+ foaf:name "Joe Bob";
+</del>
+<div class="example"><div class="example-title"><span>Example 61</span>: A list of values in Turtle</div><pre class="example">@prefix foaf: <http://xmlns.com/foaf/0.1/> .
+<ins class="diff-chg">
+<http://example.org/people#joebob> a foaf:Person;
+ foaf:name "Joe Bob";
+</ins>
+foaf:nick
+(
+"joe"
+"bob"
+"jaybee"
+)
+.
+</pre>
+</div>
+<del class="diff-old">{
+ "@context":
+ {
+ "foaf": "http://xmlns.com/foaf/0.1/"
+ },
+ "@id": "http://example.org/people#joebob",
+ "@type": "foaf:Person",
+ "foaf:name": "Joe Bob",
+ "foaf:nick":
+ {
+ "@list": [ "joe", "bob", "jaybee" ]
+ }
+</del>
+<div class="example"><div class="example-title"><span>Example 62</span>: Same example with a list of values in JSON-LD</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+ "foaf": "http://xmlns.com/foaf/0.1/"
+ },
+ "@id": "http://example.org/people#joebob",
+ "@type": "foaf:Person",
+ "foaf:name": "Joe Bob",
+ "foaf:nick":
+ {
+ "@list": [ "joe", "bob", "jaybee" ]
+ }
+</ins>
+}
+</pre>
+</div>
+</section>
+</section>
+<section id="rdfa">
+<h3>
+<span class="secno">
+D.2
+</span>
+RDFa
+</h3>
+<p>
+The
+following
+example
+describes
+three
+people
+with
+their
+respective
+names
+and
+homepages
+in
+<ins class="diff-new">RDFa
+</ins>
+[
+<cite>
+<a href="#bib-RDFA-CORE" class="bibref">
+RDFA-CORE
+</a>
+</cite>
+].
+</p>
+<del class="diff-old">>
+ <ul>
+ <li >
+ <a >Bob</a>
+ </li>
+ <li >
+ <a >Eve</a>
+ </li>
+ <li >
+ <a >Manu</a>
+ </li>
+ </ul>
+</del>
+<div class="example"><div class="example-title"><span>Example 63</span>: RDFa fragment that describes three people</div><pre class="example"><div <span class="diff">prefix="foaf: http://xmlns.com/foaf/0.1/"</span>>
+<ins class="diff-chg"> <ul>
+ <li <span class="diff">typeof="foaf:Person"</span>>
+ <a <span class="diff">rel="foaf:homepage" href="http://example.com/bob/" property="foaf:name"</span>>Bob</a>
+ </li>
+ <li <span class="diff">typeof="foaf:Person"</span>>
+ <a <span class="diff">rel="foaf:homepage" href="http://example.com/eve/" property="foaf:name"</span>>Eve</a>
+ </li>
+ <li <span class="diff">typeof="foaf:Person"</span>>
+ <a <span class="diff">rel="foaf:homepage" href="http://example.com/manu/" property="foaf:name"</span>>Manu</a>
+ </li>
+ </ul>
+</ins>
+</div>
+</pre>
+</div>
+<p>
+An
+example
+JSON-LD
+implementation
+using
+a
+single
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>
+is
+described
+below.
+</p>
+<del class="diff-old">{
+ "@context":
+ {
+ "foaf": "http://xmlns.com/foaf/0.1/"
+ },
+ "@graph":
+ [
+ {
+ "@type": "foaf:Person",
+ "foaf:homepage": "http://example.com/bob/",
+ "foaf:name": "Bob"
+ },
+ {
+ "@type": "foaf:Person",
+ "foaf:homepage": "http://example.com/eve/",
+ "foaf:name": "Eve"
+ },
+ {
+ "@type": "foaf:Person",
+ "foaf:homepage": "http://example.com/manu/",
+ "foaf:name": "Manu"
+ }
+ ]
+</del>
+<div class="example"><div class="example-title"><span>Example 64</span>: Same description in JSON-LD (context shared among node objects)</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+ "foaf": "http://xmlns.com/foaf/0.1/"
+ },
+ "@graph":
+ [
+ {
+ "@type": "foaf:Person",
+ "foaf:homepage": "http://example.com/bob/",
+ "foaf:name": "Bob"
+ },
+ {
+ "@type": "foaf:Person",
+ "foaf:homepage": "http://example.com/eve/",
+ "foaf:name": "Eve"
+ },
+ {
+ "@type": "foaf:Person",
+ "foaf:homepage": "http://example.com/manu/",
+ "foaf:name": "Manu"
+ }
+ ]
+</ins>
+}
+</pre>
+</div>
+</section>
+<section id="microformats">
+<h3>
+<span class="secno">
+D.3
+</span>
+Microformats
+</h3>
+<p>
+The
+following
+example
+uses
+a
+simple
+Microformats
+hCard
+<del class="diff-old">([
+</del>
+<ins class="diff-chg">example
+to
+express
+how
+Microformats
+[
+</ins>
+<cite>
+<a href="#bib-MICROFORMATS" class="bibref">
+MICROFORMATS
+</a>
+</cite>
+<del class="diff-old">])
+example
+to
+express
+how
+the
+Microformat
+is
+</del>
+<ins class="diff-chg">]
+are
+</ins>
+represented
+in
+JSON-LD.
+</p>
+<del class="diff-old"><div class="vcard">
+ <a class="url fn" href="http://tantek.com/">Tantek Çelik</a>
+</del>
+<div class="example"><div class="example-title"><span>Example 65</span>: HTML fragment with a simple Microformats hCard</div><pre class="example"><div class="vcard">
+<ins class="diff-chg"> <a class="url fn" href="http://tantek.com/">Tantek Çelik</a>
+</ins>
+</div>
+</pre>
+</div>
+<p>
+The
+representation
+of
+the
+hCard
+expresses
+the
+Microformat
+terms
+in
+the
+<a href="#dfn-context" title="context" class="tref internalDFN">
+context
+</a>
+and
+uses
+them
+directly
+for
+the
+<code>
+url
+</code>
+and
+<code>
+fn
+</code>
+properties.
+Also
+note
+that
+the
+Microformat
+to
+JSON-LD
+processor
+has
+generated
+the
+proper
+URL
+type
+for
+<code>
+http://tantek.com/
+</code>.
+</p>
+<del class="diff-old">{
+ "@context":
+ {
+ "vcard": "http://microformats.org/profile/hcard#vcard",
+ "url":
+ {
+ "@id": "http://microformats.org/profile/hcard#url",
+ "@type": "@id"
+ },
+ "fn": "http://microformats.org/profile/hcard#fn"
+ },
+ "@type": "vcard",
+ "url": "http://tantek.com/",
+ "fn": "Tantek Çelik"
+</del>
+<div class="example"><div class="example-title"><span>Example 66</span>: Same hCard representation in JSON-LD</div><pre class="example">{
+<ins class="diff-chg"> "@context":
+ {
+ "vcard": "http://microformats.org/profile/hcard#vcard",
+ "url":
+ {
+ "@id": "http://microformats.org/profile/hcard#url",
+ "@type": "@id"
+ },
+ "fn": "http://microformats.org/profile/hcard#fn"
+ },
+ "@type": "vcard",
+ "url": "http://tantek.com/",
+ "fn": "Tantek Çelik"
+</ins>
+}
+</pre>
+</div>
+</section>
+<section id="microdata">
+<h3>
+<span class="secno">
+D.4
+</span>
+Microdata
+</h3>
+<p>
+The
+<ins class="diff-new">HTML
+Microdata
+</ins>
+[
+<cite>
+<a href="#bib-MICRODATA" class="bibref">
+MICRODATA
+</a>
+</cite>
+]
+example
+below
+expresses
+book
+information
+as
+a
+<del class="diff-old">microdata
+</del>
+<ins class="diff-chg">Microdata
+</ins>
+Work
+item.
+</p>
+<del class="diff-old"><dl itemscope
+ itemtype="http://purl.org/vocab/frbr/core#Work"
+ itemid="http://purl.oreilly.com/works/45U8QJGZSQKDH8N">
+ <dt>Title</dt>
+ <dd><cite itemprop="http://purl.org/dc/terms/title">Just a Geek</cite></dd>
+ <dt>By</dt>
+ <dd><span itemprop="http://purl.org/dc/terms/creator">Wil Wheaton</span></dd>
+ <dt>Format</dt>
+ <dd itemprop="http://purl.org/vocab/frbr/core#realization"
+ itemscope
+ itemtype="http://purl.org/vocab/frbr/core#Expression"
+ itemid="http://purl.oreilly.com/products/9780596007683.BOOK">
+ <link itemprop="http://purl.org/dc/terms/type" href="http://purl.oreilly.com/product-types/BOOK">
+ Print
+ </dd>
+ <dd itemprop="http://purl.org/vocab/frbr/core#realization"
+ itemscope
+ itemtype="http://purl.org/vocab/frbr/core#Expression"
+ itemid="http://purl.oreilly.com/products/9780596802189.EBOOK">
+ <link itemprop="http://purl.org/dc/terms/type" href="http://purl.oreilly.com/product-types/EBOOK">
+ Ebook
+ </dd>
+</del>
+<div class="example"><div class="example-title"><span>Example 67</span>: HTML fragments that describes a book using microdata</div><pre class="example"><dl itemscope
+<ins class="diff-chg"> itemtype="http://purl.org/vocab/frbr/core#Work"
+ itemid="http://purl.oreilly.com/works/45U8QJGZSQKDH8N">
+ <dt>Title</dt>
+ <dd><cite itemprop="http://purl.org/dc/terms/title">Just a Geek</cite></dd>
+ <dt>By</dt>
+ <dd><span itemprop="http://purl.org/dc/terms/creator">Wil Wheaton</span></dd>
+ <dt>Format</dt>
+ <dd itemprop="http://purl.org/vocab/frbr/core#realization"
+ itemscope
+ itemtype="http://purl.org/vocab/frbr/core#Expression"
+ itemid="http://purl.oreilly.com/products/9780596007683.BOOK">
+ <link itemprop="http://purl.org/dc/terms/type" href="http://purl.oreilly.com/product-types/BOOK">
+ Print
+ </dd>
+ <dd itemprop="http://purl.org/vocab/frbr/core#realization"
+ itemscope
+ itemtype="http://purl.org/vocab/frbr/core#Expression"
+ itemid="http://purl.oreilly.com/products/9780596802189.EBOOK">
+ <link itemprop="http://purl.org/dc/terms/type" href="http://purl.oreilly.com/product-types/EBOOK">
+ Ebook
+ </dd>
+</ins>
+</dl>
+</pre>
+</div>
+<p>
+Note
+that
+the
+JSON-LD
+representation
+of
+the
+Microdata
+information
+stays
+true
+to
+the
+desires
+of
+the
+Microdata
+community
+to
+avoid
+contexts
+and
+instead
+refer
+to
+items
+by
+their
+full
+<a href="#dfn-iri" title="iri" class="tref internalDFN">
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>
+</a>.
+</p>
+<del class="diff-old">[
+ {
+ "@id": "http://purl.oreilly.com/works/45U8QJGZSQKDH8N",
+ "@type": "http://purl.org/vocab/frbr/core#Work",
+ "http://purl.org/dc/terms/title": "Just a Geek",
+ "http://purl.org/dc/terms/creator": "Whil Wheaton",
+ "http://purl.org/vocab/frbr/core#realization":
+ [
+ "http://purl.oreilly.com/products/9780596007683.BOOK",
+ "http://purl.oreilly.com/products/9780596802189.EBOOK"
+ ]
+ },
+ {
+ "@id": "http://purl.oreilly.com/products/9780596007683.BOOK",
+ "@type": "http://purl.org/vocab/frbr/core#Expression",
+ "http://purl.org/dc/terms/type": "http://purl.oreilly.com/product-types/BOOK"
+ },
+ {
+ "@id": "http://purl.oreilly.com/products/9780596802189.EBOOK",
+ "@type": "http://purl.org/vocab/frbr/core#Expression",
+ "http://purl.org/dc/terms/type": "http://purl.oreilly.com/product-types/EBOOK"
+ }
+</del>
+<div class="example"><div class="example-title"><span>Example 68</span>: Same book description in JSON-LD (avoiding contexts)</div><pre class="example">[
+<ins class="diff-chg"> {
+ "@id": "http://purl.oreilly.com/works/45U8QJGZSQKDH8N",
+ "@type": "http://purl.org/vocab/frbr/core#Work",
+ "http://purl.org/dc/terms/title": "Just a Geek",
+ "http://purl.org/dc/terms/creator": "Whil Wheaton",
+ "http://purl.org/vocab/frbr/core#realization":
+ [
+ "http://purl.oreilly.com/products/9780596007683.BOOK",
+ "http://purl.oreilly.com/products/9780596802189.EBOOK"
+ ]
+ },
+ {
+ "@id": "http://purl.oreilly.com/products/9780596007683.BOOK",
+ "@type": "http://purl.org/vocab/frbr/core#Expression",
+ "http://purl.org/dc/terms/type": "http://purl.oreilly.com/product-types/BOOK"
+ },
+ {
+ "@id": "http://purl.oreilly.com/products/9780596802189.EBOOK",
+ "@type": "http://purl.org/vocab/frbr/core#Expression",
+ "http://purl.org/dc/terms/type": "http://purl.oreilly.com/product-types/EBOOK"
+ }
+</ins>
+]
+</pre>
+</div>
+</section>
+</section>
+<section id="iana-considerations" class="appendix informative">
+<h2>
+<span class="secno">
+E.
+</span>
+IANA
+Considerations
+</h2>
+<p>
+<em>
+This
+section
+is
+non-normative.
+</em>
+</p>
+<p>
+This
+section
+is
+included
+merely
+for
+standards
+community
+review
+and
+will
+be
+submitted
+to
+the
+Internet
+Engineering
+Steering
+Group
+if
+this
+specification
+becomes
+a
+W3C
+Recommendation.
+</p>
+<h2 id="application-ld-json">
+application/ld+json
+</h2>
+<dl>
+<dt>
+Type
+name:
+</dt>
+<dd>
+application
+</dd>
+<dt>
+Subtype
+name:
+</dt>
+<dd>
+ld+json
+</dd>
+<dt>
+Required
+parameters:
+</dt>
+<dd>
+None
+</dd>
+<dt>
+Optional
+parameters:
+</dt>
+<dd>
+<dl>
+<dt>
+<code>
+profile
+</code>
+</dt>
+<dd>
+<p>
+A
+whitespace-separated
+list
+of
+IRIs
+identifying
+specific
+constraints
+or
+conventions
+that
+apply
+to
+a
+JSON-LD
+document.
+A
+profile
+<em title="must not" class="rfc2119">
+must
+not
+</em>
+change
+the
+semantics
+of
+the
+resource
+<ins class="diff-new">representation
+when
+processed
+without
+profile
+knowledge,
+so
+that
+clients
+both
+with
+and
+without
+knowledge
+of
+a
+profiled
+resource
+can
+safely
+use
+the
+same
+</ins>
+representation.
+The
+<code>
+profile
+</code>
+parameter
+<em title="may" class="rfc2119">
+may
+</em>
+also
+be
+used
+by
+clients
+to
+express
+their
+preferences
+in
+the
+content
+negotiation
+process.
+It
+is
+<em title="recommended" class="rfc2119">
+recommended
+</em>
+that
+profile
+IRIs
+are
+dereferenceable
+and
+provide
+useful
+documentation
+at
+that
+<abbr title="Internationalized Resource Identifier">
+IRI
+</abbr>.
+<ins class="diff-new">For
+more
+information
+and
+background
+please
+refer
+to
+[
+</ins><cite><a href="#bib-PROFILE-LINK" class="bibref"><ins class="diff-new">
+PROFILE-LINK
+</ins></a></cite><ins class="diff-new">
+].
+</ins></p><p>
+This
+specification
+defines
+four
+values
+for
+the
+<code>
+profile
+</code>
+parameter.
+To
+request
+or
+specify
+Expanded
+JSON-LD
+document
+form,
+the
+<abbr title="Internationalized Resource Identifier">
+<ins class="diff-new">IRI
+</ins></abbr>
+<code>
+http://www.w3.org/ns/json-ld#expanded
+</code>
+<del class="diff-old">URL
+</del>
+<em title="should" class="rfc2119">
+should
+</em>
+be
+used.
+To
+request
+or
+specify
+Expanded,
+Flattened
+JSON-LD
+document
+form,
+the
+<abbr title="Internationalized Resource Identifier">
+<ins class="diff-new">IRI
+</ins></abbr>
+<code>
+http://www.w3.org/ns/json-ld#expanded-flattened
+</code>
+<del class="diff-old">URL
+</del>
+<em title="should" class="rfc2119">
+should
+</em>
+be
+used.
+To
+request
+or
+specify
+Compacted
+JSON-LD
+document
+form,
+the
+<abbr title="Internationalized Resource Identifier">
+<ins class="diff-new">IRI
+</ins></abbr>
+<code>
+http://www.w3.org/ns/json-ld#compacted
+</code>
+<del class="diff-old">URL
+</del>
+<em title="should" class="rfc2119">
+should
+</em>
+be
+used.
+To
+request
+or
+specify
+Compacted,
+Flattened
+JSON-LD
+document
+form,
+the
+<abbr title="Internationalized Resource Identifier">
+<ins class="diff-new">IRI
+</ins></abbr>
+<code>
+http://www.w3.org/ns/json-ld#compacted-flattened
+</code>
+<del class="diff-old">URL
+</del>
+<em title="should" class="rfc2119">
+should
+</em>
+be
+used.
+<ins class="diff-new">Please
+note
+that,
+according
+[
+</ins><cite><a href="#bib-HTTP11" class="bibref"><ins class="diff-new">
+HTTP11
+</ins></a></cite><ins class="diff-new">
+],
+the
+value
+of
+the
+</ins><code><ins class="diff-new">
+profile
+</ins></code><ins class="diff-new">
+parameter
+has
+to
+be
+enclosed
+in
+quotes
+(
+</ins><code><ins class="diff-new">
+"
+</ins></code><ins class="diff-new">
+)
+because
+it
+contains
+special
+characters
+and,
+in
+some
+cases,
+whitespace.
+</ins></p>
+</dd>
+</dl>
+</dd>
+<dt>
+Encoding
+considerations:
+</dt>
+<dd>
+<del class="diff-old">The
+same
+as
+the
+application/json
+MIME
+media
+type.
+</del>
+<ins class="diff-chg">See
+RFC 6839,
+section
+3.1.
+</ins>
+</dd>
+<dt>
+Security
+considerations:
+</dt>
+<dd>
+Since
+JSON-LD
+is
+intended
+to
+be
+a
+pure
+data
+exchange
+format
+for
+directed
+graphs,
+the
+serialization
+<em title="should not" class="rfc2119">
+should
+not
+</em>
+be
+passed
+through
+a
+code
+execution
+mechanism
+such
+as
+JavaScript's
+<code>
+eval()
+</code>
+<del class="diff-old">function.
+It
+is
+recommended
+that
+a
+conforming
+parser
+does
+not
+attempt
+</del>
+<ins class="diff-chg">function
+</ins>
+to
+<del class="diff-old">directly
+evaluate
+the
+JSON-LD
+serialization
+and
+instead
+purely
+parse
+the
+input
+into
+a
+language-native
+data
+structure.
+</del>
+<ins class="diff-chg">be
+parsed.
+</ins>
+<br>
+JSON-LD
+contexts
+that
+are
+loaded
+from
+the
+Web
+over
+non-secure
+connections,
+such
+as
+HTTP,
+run
+the
+risk
+of
+modifying
+the
+JSON-LD
+<a href="#dfn-active-context" title="active-context" class="tref internalDFN">
+active
+context
+</a>
+in
+a
+way
+that
+could
+compromise
+security.
+It
+is
+advised
+that
+any
+application
+that
+depends
+on
+a
+remote
+context
+for
+mission
+critical
+purposes
+vet
+and
+cache
+the
+remote
+context
+before
+allowing
+the
+system
+to
+use
+it.
+<br>
+<ins class="diff-new">JSON-LD
+allows
+the
+substitution
+of
+long
+IRIs
+with
+short
+terms
+and
+the
+compression
+of
+multiple
+properties
+into
+a
+single
+property
+generator.
+Therefore,
+JSON-LD
+documents
+may
+expand
+enormously
+when
+processed
+and,
+in
+the
+worst
+case,
+the
+resulting
+data
+might
+consume
+all
+of
+the
+recipient's
+resources.
+Applications
+should
+treat
+any
+data
+with
+due
+skepticism.
+</ins>
+</dd>
+<dt>
+Interoperability
+considerations:
+</dt>
+<dd>
+Not
+Applicable
+</dd>
+<dt>
+Published
+specification:
+</dt>
+<dd>
+The
+<a href="http://json-ld.org/spec/latest/">
+JSON-LD
+</a>
+specification.
+</dd>
+<dt>
+Applications
+that
+use
+this
+media
+type:
+</dt>
+<dd>
+Any
+programming
+environment
+that
+requires
+the
+exchange
+of
+directed
+graphs.
+Implementations
+of
+JSON-LD
+have
+been
+created
+for
+JavaScript,
+Python,
+Ruby,
+PHP,
+and
+C++.
+</dd>
+<dt>
+Additional
+information:
+</dt>
+<dd>
+<dl>
+<dt>
+Magic
+number(s):
+</dt>
+<dd>
+Not
+Applicable
+</dd>
+<dt>
+File
+extension(s):
+</dt>
+<dd>.jsonld
+</dd>
+<dt>
+Macintosh
+file
+type
+code(s):
+</dt>
+<dd>
+TEXT
+</dd>
+</dl>
+</dd>
+<dt>
+Person
+&
+email
+address
+to
+contact
+for
+further
+information:
+</dt>
+<dd>
+Manu
+Sporny
+<msporny@digitalbazaar.com>
+</dd>
+<dt>
+Intended
+usage:
+</dt>
+<dd>
+Common
+</dd>
+<dt>
+Restrictions
+on
+usage:
+</dt>
+<dd>
+None
+</dd>
+<dt>
+Author(s):
+</dt>
+<dd>
+Manu
+Sporny,
+Dave
+Longley,
+Gregg
+Kellogg,
+Markus
+Lanthaler,
+Niklas
+Lindström
+</dd>
+<dt>
+Change
+controller:
+</dt>
+<dd>
+W3C
+</dd>
+</dl>
+<p>
+Fragment
+identifiers
+used
+with
+<a href="#application-ld-json">
+application/ld+json
+</a>
+resources
+<em title="may" class="rfc2119">
+may
+</em>
+identify
+a
+node
+in
+a
+<a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">
+JSON-LD
+graph
+</a>
+expressed
+in
+the
+resource.
+This
+idiom,
+which
+is
+also
+used
+in
+RDF
+[
+<cite>
+<a href="#bib-RDF-CONCEPTS" class="bibref">
+RDF-CONCEPTS
+</a>
+</cite>
+],
+gives
+a
+simple
+way
+to
+"mint"
+new,
+document-local
+IRIs
+to
+label
+nodes
+and
+therefore
+contributes
+considerably
+to
+the
+expressive
+power
+of
+JSON-LD.
+</p>
+</section>
+<section id="acknowledgements" class="appendix informative">
+<h2>
+<span class="secno">
+F.
+</span>
+Acknowledgements
+</h2>
+<p>
+<em>
+This
+section
+is
+non-normative.
+</em>
+</p>
+<p>
+The
+authors
+would
+like
+to
+extend
+a
+deep
+appreciation
+and
+the
+most
+sincere
+thanks
+to
+Mark
+Birbeck,
+who
+contributed
+foundational
+concepts
+to
+JSON-LD
+via
+his
+work
+on
+RDFj.
+JSON-LD
+uses
+a
+number
+of
+core
+concepts
+introduced
+in
+RDFj,
+such
+as
+the
+context
+as
+a
+mechanism
+to
+provide
+an
+environment
+for
+interpreting
+JSON
+data.
+Mark
+had
+also
+been
+very
+involved
+in
+the
+work
+on
+RDFa
+as
+well.
+RDFj
+built
+upon
+that
+work.
+JSON-LD
+exists
+because
+of
+the
+work
+and
+ideas
+he
+started
+nearly
+a
+decade
+ago
+in
+2004.
+</p>
+<p>
+A
+large
+amount
+of
+thanks
+goes
+out
+to
+the
+JSON-LD
+Community
+Group
+participants
+who
+worked
+through
+many
+of
+the
+technical
+issues
+on
+the
+mailing
+list
+and
+the
+weekly
+telecons
+-
+of
+special
+mention
+are
+François
+Daoust,
+Stéphane
+Corlosquet,
+Lin
+Clark,
+and
+Zdenko
+'Denny'
+Vrandečić.
+</p>
+<p>
+The
+work
+of
+David
+I.
+Lehn
+and
+Mike
+Johnson
+are
+appreciated
+for
+reviewing,
+and
+performing
+several
+early
+implementations
+of
+the
+specification.
+Thanks
+also
+to
+Ian
+Davis
+for
+this
+work
+on
+RDF/JSON.
+</p>
+<p>
+Thanks
+to
+the
+following
+individuals,
+in
+order
+of
+their
+first
+name,
+for
+their
+input
+on
+the
+specification:
+Adrian
+Walker,
+Alexandre
+Passant,
+Andy
+Seaborne,
+Ben
+Adida,
+Blaine
+Cook,
+Bradley
+Allen,
+Brian
+Peterson,
+Bryan
+Thompson,
+Conal
+Tuohy,
+Dan
+Brickley,
+Danny
+Ayers,
+Daniel
+Leja,
+Dave
+Reynolds,
+David
+I.
+Lehn,
+David
+Wood,
+Dean
+Landolt,
+Ed
+Summers,
+elf
+Pavlik,
+Eric
+Prud'hommeaux,
+<ins class="diff-new">Erik
+Wilde,
+</ins>
+Fabian
+Christ,
+Jon
+A.
+Frost,
+Gavin
+Carothers,
+Glenn
+McDonald,
+Guus
+Schreiber,
+Henri
+Bergius,
+Jose
+María
+Alvarez
+Rodríguez,
+Ivan
+Herman,
+Jack
+Moffitt,
+Josh
+Mandel,
+KANZAKI
+Masahide,
+Kingsley
+Idehen,
+Kuno
+Woudt,
+Larry
+Garfield,
+Mark
+Baker,
+Mark
+MacGillivray,
+Marko
+Rodriguez,
+Melvin
+Carvalho,
+Nathan
+Rixham,
+Olivier
+Grisel,
+Paolo
+Ciccarese,
+Pat
+Hayes,
+Patrick
+Logan,
+<ins class="diff-new">Paul
+Kuykendall,
+</ins>
+Pelle
+Braendgaard,
+Peter
+Williams,
+Pierre-Antoine
+Champin,
+Richard
+Cyganiak,
+Roy
+T.
+Fielding,
+Sandro
+Hawke,
+Srecko
+Joksimovic,
+Stephane
+Fellah,
+Steve
+Harris,
+Ted
+Thibodeau
+Jr.,
+Thomas
+Steiner,
+Tim
+Bray,
+Tom
+Morris,
+Tristan
+King,
+Sergio
+Fernández,
+Werner
+Wilms,
+and
+William
+<del class="diff-old">Waites
+</del>
+<ins class="diff-chg">Waites.
+</ins>
+</p>
+</section>
+<section rel="bibo:chapter" resource="#references" typeof="bibo:Chapter" class="appendix" id="references">
+<h2>
+<span class="secno">
+G.
+</span>
+References
+</h2>
+<section rel="bibo:chapter" resource="#normative-references" typeof="bibo:Chapter" id="normative-references">
+<h3>
+<span class="secno">
+G.1
+</span>
+Normative
+references
+</h3>
+<dl about="" class="bibliography">
+<dt id="bib-BCP47">
+[BCP47]
+</dt>
+<dd rel="dcterms:requires">
+A.
+Phillips;
+M.
+Davis.
+<a href="http://tools.ietf.org/html/bcp47">
+<cite>
+Tags
+for
+Identifying
+Languages
+</cite>
+</a>.
+September
+2009.
+IETF
+Best
+Current
+Practice.
+URL:
+<a href="http://tools.ietf.org/html/bcp47">
+http://tools.ietf.org/html/bcp47
+</a>
+</dd>
+<dt id="bib-RDF-CONCEPTS">
+[RDF-CONCEPTS]
+</dt>
+<dd rel="dcterms:requires">
+Richard
+Cyganiak,
+David
+Wood,
+Editors.
+<cite>
+<a href="http://www.w3.org/TR/2013/WD-rdf11-concepts-20130115/">
+RDF
+1.1
+Concepts
+and
+Abstract
+Syntax.
+</a>
+</cite>
+15
+January
+2013.
+W3C
+Working
+Draft
+(work
+in
+progress).
+URL:
+<a href="http://www.w3.org/TR/2013/WD-rdf11-concepts-20130115/">
+http://www.w3.org/TR/2013/WD-rdf11-concepts-20130115/
+</a>
+</dd>
+<dt id="bib-RFC2119">
+[RFC2119]
+</dt>
+<dd rel="dcterms:requires">
+S.
+Bradner.
+<a href="http://www.ietf.org/rfc/rfc2119.txt">
+<cite>
+Key
+words
+for
+use
+in
+RFCs
+to
+Indicate
+Requirement
+Levels.
+</cite>
+</a>
+March
+1997.
+Internet
+RFC
+2119.
+URL:
+<a href="http://www.ietf.org/rfc/rfc2119.txt">
+http://www.ietf.org/rfc/rfc2119.txt
+</a>
+</dd>
+<dt id="bib-RFC3987">
+[RFC3987]
+</dt>
+<dd rel="dcterms:requires">
+M.
+Dürst;
+M.
+Suignard.
+<a href="http://www.ietf.org/rfc/rfc3987.txt">
+<cite>
+Internationalized
+Resource
+Identifiers
+<del class="diff-old">(IRIs).
+</del>
+<ins class="diff-chg">(IRIs)
+</ins>
+</cite>
+</a>.
+January
+2005.
+<del class="diff-old">Internet
+</del>
+RFC
+3987.
+URL:
+<a href="http://www.ietf.org/rfc/rfc3987.txt">
+http://www.ietf.org/rfc/rfc3987.txt
+</a>
+</dd>
+<dt id="bib-RFC4627">
+[RFC4627]
+</dt>
+<dd rel="dcterms:requires">
+D.
+Crockford.
+<a href="http://www.ietf.org/rfc/rfc4627.txt">
+<cite>
+The
+application/json
+Media
+Type
+for
+JavaScript
+Object
+Notation
+(JSON)
+</cite>
+</a>.
+July
+2006.
+<del class="diff-old">Internet
+</del>
+RFC
+4627.
+URL:
+<a href="http://www.ietf.org/rfc/rfc4627.txt">
+http://www.ietf.org/rfc/rfc4627.txt
+</a>
+</dd>
+<dt id="bib-RFC5988">
+[RFC5988]
+</dt>
+<dd rel="dcterms:requires">
+M.
+Nottingham,
+Editor.
+<cite>
+<a href="http://tools.ietf.org/rfc/rfc5988">
+Web
+Linking
+</a>.
+</cite>
+October
+2010.
+Internet
+RFC
+5988.
+URL:
+<a href="http://tools.ietf.org/rfc/rfc5988.txt">
+http://tools.ietf.org/rfc/rfc5988.txt
+</a>
+</dd>
+</dl>
+</section>
+<section rel="bibo:chapter" resource="#informative-references" typeof="bibo:Chapter" id="informative-references">
+<h3>
+<span class="secno">
+G.2
+</span>
+Informative
+references
+</h3>
+<dl about="" class="bibliography">
+<dt id="bib-HTTP11">
+<ins class="diff-chg">[HTTP11]
+</ins></dt><dd rel="dcterms:references"><ins class="diff-chg">
+R.
+Fielding
+et
+al.
+</ins><a href="http://www.ietf.org/rfc/rfc2616.txt"><cite><ins class="diff-chg">
+Hypertext
+Transfer
+Protocol
+-
+HTTP/1.1
+</ins></cite></a>.<ins class="diff-chg">
+June
+1999.
+RFC
+2616.
+URL:
+</ins><a href="http://www.ietf.org/rfc/rfc2616.txt"><ins class="diff-chg">
+http://www.ietf.org/rfc/rfc2616.txt
+</ins></a></dd>
+<dt id="bib-JSON-LD-API">
+[JSON-LD-API]
+</dt>
+<dd rel="dcterms:references">
+Markus
+Lanthaler,
+Gregg
+Kellogg,
+Manu
+Sporny,
+Editors.
+<cite>
+<a href="http://json-ld.org/spec/latest/json-ld-api/">
+JSON-LD
+1.0
+Processing
+Algorithms
+and
+API
+</a>.
+</cite>
+W3C
+Editor's
+Draft
+(work
+in
+progress).
+URL:
+<a href="http://json-ld.org/spec/latest/json-ld-api/">
+http://json-ld.org/spec/latest/json-ld-api/
+</a>
+</dd>
+<dt id="bib-MICRODATA">
+[MICRODATA]
+</dt>
+<dd rel="dcterms:references">
+Ian
+Hickson,
+Editor.
+<cite>
+<a href="http://www.w3.org/TR/2012/WD-microdata-20120329/">
+HTML
+Microdata
+</a>.
+</cite>
+29
+March
+2012.
+W3C
+Working
+Draft
+(work
+in
+progress).
+URL:
+<a href="http://www.w3.org/TR/2012/WD-microdata-20120329/">
+http://www.w3.org/TR/2012/WD-microdata-20120329/
+</a>
+</dd>
+<dt id="bib-MICROFORMATS">
+[MICROFORMATS]
+</dt>
+<dd rel="dcterms:references">
+<a href="http://microformats.org">
+<cite>
+Microformats
+</cite>
+</a>.
+URL:
+<a href="http://microformats.org">
+http://microformats.org
+</a>
+</dd>
+<dt id="bib-PROFILE-LINK">
+<ins class="diff-new">[PROFILE-LINK]
+</ins></dt><dd rel="dcterms:references"><ins class="diff-new">
+Erik
+Wilde.
+</ins><cite><a href="http://tools.ietf.org/html/draft-wilde-profile-link"><ins class="diff-new">
+The
+'profile'
+Link
+Relation
+Type
+</ins></a>.</cite><ins class="diff-new">
+17
+October
+2012.
+IETF
+Internet
+Draft
+(work
+in
+progress).
+URL:
+</ins><a href="http://tools.ietf.org/html/draft-wilde-profile-link"><ins class="diff-new">
+http://tools.ietf.org/html/draft-wilde-profile-link
+</ins></a></dd>
+<dt id="bib-RDF-SCHEMA">
+[RDF-SCHEMA]
+</dt>
+<dd rel="dcterms:references">
+Dan
+Brickley;
+Ramanathan
+V.
+Guha.
+<a href="http://www.w3.org/TR/2004/REC-rdf-schema-20040210">
+<cite>
+RDF
+Vocabulary
+Description
+Language
+1.0:
+RDF
+<del class="diff-old">Schema.
+</del>
+<ins class="diff-chg">Schema
+</ins>
+</cite>
+</a>.
+10
+February
+2004.
+W3C
+Recommendation.
+URL:
+<a href="http://www.w3.org/TR/2004/REC-rdf-schema-20040210">
+http://www.w3.org/TR/2004/REC-rdf-schema-20040210
+</a>
+</dd>
+<dt id="bib-RDFA-CORE">
+[RDFA-CORE]
+</dt>
+<dd rel="dcterms:references">
+Shane
+<del class="diff-old">McCarron;
+</del>
+<ins class="diff-chg">McCarron
+</ins>
+et
+al.
+<a href="http://www.w3.org/TR/2012/REC-rdfa-core-20120607/">
+<cite>
+RDFa
+Core
+1.1:
+Syntax
+and
+processing
+rules
+for
+embedding
+RDF
+through
+<del class="diff-old">attributes.
+</del>
+<ins class="diff-chg">attributes
+</ins>
+</cite>
+</a>.
+7
+June
+2012.
+W3C
+Recommendation.
+URL:
+<a href="http://www.w3.org/TR/2012/REC-rdfa-core-20120607/">
+http://www.w3.org/TR/2012/REC-rdfa-core-20120607/
+</a>
+</dd>
+<dt id="bib-TURTLE-TR">
+[TURTLE-TR]
+</dt>
+<dd rel="dcterms:references">
+Eric
+Prud'hommeaux,
+Gavin
+Carothers,
+Editors.
+<cite>
+<a href="http://www.w3.org/TR/2011/WD-turtle-20110809/">
+Turtle:
+Terse
+RDF
+Triple
+Language.
+</a>
+</cite>
+09
+August
+2011.
+W3C
+Working
+Draft
+(work
+in
+progress).
+URL:
+<a href="http://www.w3.org/TR/2011/WD-turtle-20110809/">
+http://www.w3.org/TR/2011/WD-turtle-20110809/
+</a>
+</dd>
+</dl>
+</section>
+</section>
+</body>
+</html>
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/spec/FCGS/json-ld-syntax/20130222/index.html Fri Feb 22 12:58:40 2013 +0100
@@ -0,0 +1,3260 @@
+<!DOCTYPE html>
+<html lang="en" dir="ltr" prefix="bibo: http://purl.org/ontology/bibo/" typeof="bibo:Document">
+<head>
+<title>JSON-LD 1.0</title>
+<meta http-equiv="content-type" content="text/html; charset=UTF-8">
+
+
+
+<style type="text/css">
+ .diff { font-weight:bold; color:#0a3; }
+ table, thead, tr, td { padding: 5px; border-width: 1px; border-spacing: 0px; border-style: solid; border-collapse: collapse;}
+</style>
+<style>/*****************************************************************
+ * ReSpec 3 CSS
+ * Robin Berjon - http://berjon.com/
+ *****************************************************************/
+
+/* --- INLINES --- */
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+ font-variant: small-caps;
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+ border: none;
+}
+
+dfn {
+ font-weight: bold;
+}
+
+a.internalDFN {
+ color: inherit;
+ border-bottom: 1px solid #99c;
+ text-decoration: none;
+}
+
+a.externalDFN {
+ color: inherit;
+ border-bottom: 1px dotted #ccc;
+ text-decoration: none;
+}
+
+a.bibref {
+ text-decoration: none;
+}
+
+cite .bibref {
+ font-style: normal;
+}
+
+code {
+ color: #ff4500;
+}
+
+
+/* --- --- */
+ol.algorithm { counter-reset:numsection; list-style-type: none; }
+ol.algorithm li { margin: 0.5em 0; }
+ol.algorithm li:before { font-weight: bold; counter-increment: numsection; content: counters(numsection, ".") ") "; }
+
+/* --- TOC --- */
+.toc a, .tof a {
+ text-decoration: none;
+}
+
+a .secno, a .figno {
+ color: #000;
+}
+
+ul.tof, ol.tof {
+ list-style: none outside none;
+}
+
+.caption {
+ margin-top: 0.5em;
+ font-style: italic;
+}
+
+/* --- TABLE --- */
+table.simple {
+ border-spacing: 0;
+ border-collapse: collapse;
+ border-bottom: 3px solid #005a9c;
+}
+
+.simple th {
+ background: #005a9c;
+ color: #fff;
+ padding: 3px 5px;
+ text-align: left;
+}
+
+.simple th[scope="row"] {
+ background: inherit;
+ color: inherit;
+ border-top: 1px solid #ddd;
+}
+
+.simple td {
+ padding: 3px 10px;
+ border-top: 1px solid #ddd;
+}
+
+.simple tr:nth-child(even) {
+ background: #f0f6ff;
+}
+
+/* --- DL --- */
+.section dd > p:first-child {
+ margin-top: 0;
+}
+
+.section dd > p:last-child {
+ margin-bottom: 0;
+}
+
+.section dd {
+ margin-bottom: 1em;
+}
+
+.section dl.attrs dd, .section dl.eldef dd {
+ margin-bottom: 0;
+}
+</style><style>/* --- EXAMPLES --- */
+div.example-title {
+ min-width: 7.5em;
+ color: #b9ab2d;
+}
+div.example-title span {
+ text-transform: uppercase;
+}
+aside.example, div.example, div.illegal-example {
+ padding: 0.5em;
+ margin: 1em 0;
+ position: relative;
+ clear: both;
+}
+div.illegal-example { color: red }
+div.illegal-example p { color: black }
+aside.example, div.example {
+ padding: .5em;
+ border-left-width: .5em;
+ border-left-style: solid;
+ border-color: #e0cb52;
+ background: #fcfaee;
+}
+
+aside.example div.example {
+ border-left-width: .1em;
+ border-color: #999;
+ background: #fff;
+}
+aside.example div.example div.example-title {
+ color: #999;
+}
+</style><style>/* --- ISSUES/NOTES --- */
+div.issue-title, div.note-title {
+ padding-right: 1em;
+ min-width: 7.5em;
+ color: #b9ab2d;
+}
+div.issue-title { color: #e05252; }
+div.note-title { color: #52e052; }
+div.issue-title span, div.note-title span {
+ text-transform: uppercase;
+}
+div.note, div.issue {
+ margin-top: 1em;
+ margin-bottom: 1em;
+}
+.note > p:first-child, .issue > p:first-child { margin-top: 0 }
+.issue, .note {
+ padding: .5em;
+ border-left-width: .5em;
+ border-left-style: solid;
+}
+div.issue, div.note {
+ padding: 0.5em;
+ margin: 1em 0;
+ position: relative;
+ clear: both;
+}
+span.note, span.issue { padding: .1em .5em .15em; }
+
+.issue {
+ border-color: #e05252;
+ background: #fbe9e9;
+}
+.note {
+ border-color: #52e052;
+ background: #e9fbe9;
+}
+
+
+</style><link href="http://www.w3.org/community/src/css/spec/cg-final.css" rel="stylesheet"><!--[if lt IE 9]><script src='http://www.w3.org/2008/site/js/html5shiv.js'></script><![endif]--><!--[if lt IE 9]><script src='http://www.w3.org/2008/site/js/html5shiv.js'></script><![endif]--><!--[if lt IE 9]><script src='http://www.w3.org/2008/site/js/html5shiv.js'></script><![endif]--></head>
+
+<body><div class="head">
+ <p>
+ <a href="http://www.w3.org/"><img src="http://www.w3.org/Icons/w3c_home" alt="W3C" height="48" width="72"></a>
+ </p>
+ <h1 class="title" id="title">JSON-LD 1.0</h1>
+ <h2 id="subtitle">A JSON-based Serialization for Linked Data</h2>
+ <h2 id="final-community-group-specification-22-february-2013">Final Community Group Specification 22 February 2013</h2>
+ <dl>
+
+
+
+ <dt>Latest editor's draft:</dt>
+ <dd><a href="http://dvcs.w3.org/hg/json-ld/raw-file/default/spec/latest/json-ld-syntax/index.html">http://dvcs.w3.org/hg/json-ld/raw-file/default/spec/latest/json-ld-syntax/index.html</a></dd>
+
+
+
+
+
+ <dt>Editors:</dt>
+ <dd rel="bibo:editor" inlist=""><span typeof="foaf:Person"><a rel="foaf:homepage" property="foaf:name" content="Manu Sporny" href="http://manu.sporny.org/">Manu Sporny</a>, <a rel="foaf:workplaceHomepage" href="http://digitalbazaar.com/">Digital Bazaar</a></span>
+</dd>
+<dd rel="bibo:editor" inlist=""><span typeof="foaf:Person"><a rel="foaf:homepage" property="foaf:name" content="Gregg Kellogg" href="http://greggkellogg.net/">Gregg Kellogg</a>, <a rel="foaf:workplaceHomepage" href="http://kellogg-assoc.com/">Kellogg Associates</a></span>
+</dd>
+<dd rel="bibo:editor" inlist=""><span typeof="foaf:Person"><a rel="foaf:homepage" property="foaf:name" content="Markus Lanthaler" href="http://www.markus-lanthaler.com/">Markus Lanthaler</a>, <a rel="foaf:workplaceHomepage" href="http://www.tugraz.at/">Graz University of Technology</a></span>
+</dd>
+
+
+ <dt>Authors:</dt>
+ <dd rel="dcterms:contributor"><span typeof="foaf:Person"><a rel="foaf:homepage" property="foaf:name" content="Manu Sporny" href="http://digitalbazaar.com/">Manu Sporny</a>, <a rel="foaf:workplaceHomepage" href="http://digitalbazaar.com/">Digital Bazaar</a></span>
+</dd>
+<dd rel="dcterms:contributor"><span typeof="foaf:Person"><a rel="foaf:homepage" property="foaf:name" content="Dave Longley" href="http://digitalbazaar.com/">Dave Longley</a>, <a rel="foaf:workplaceHomepage" href="http://digitalbazaar.com/">Digital Bazaar</a></span>
+</dd>
+<dd rel="dcterms:contributor"><span typeof="foaf:Person"><a rel="foaf:homepage" property="foaf:name" content="Gregg Kellogg" href="http://greggkellogg.net/">Gregg Kellogg</a>, <a rel="foaf:workplaceHomepage" href="http://kellogg-assoc.com/">Kellogg Associates</a></span>
+</dd>
+<dd rel="dcterms:contributor"><span typeof="foaf:Person"><a rel="foaf:homepage" property="foaf:name" content="Markus Lanthaler" href="http://www.markus-lanthaler.com/">Markus Lanthaler</a>, <a rel="foaf:workplaceHomepage" href="http://www.tugraz.at/">Graz University of Technology</a></span>
+</dd>
+<dd rel="dcterms:contributor"><span typeof="foaf:Person"><a rel="foaf:homepage" property="foaf:name" content="Niklas Lindström" href="http://neverspace.net/">Niklas Lindström</a></span>
+</dd>
+
+
+ </dl>
+
+ <p>
+
+ This document is also available in this non-normative format:
+
+ <a class="alt-format" href="diff-20130202.html">diff to previous version</a>
+ </p>
+
+ <p class="copyright">
+ <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> ©
+ 2010-2013
+ the Contributors to the JSON-LD 1.0 Specification, published by the
+ <a href="http://www.w3.org/2011/rdf-wg/">RDF Working Group</a> under the
+
+ <a href="https://www.w3.org/community/about/agreements/fsa/">W3C Community Final Specification Agreement (FSA)</a>.
+ A human-readable <a href="http://www.w3.org/community/about/agreements/fsa-deed/">summary</a> is available.
+
+ </p>
+ <hr>
+</div>
+<section rel="bibo:chapter" resource="#abstract" typeof="bibo:Chapter" datatype="" property="dcterms:abstract" class="introductory" id="abstract"><h2>Abstract</h2>
+ <p>JSON has proven to be a highly useful object serialization and messaging format.
+ In an attempt to harmonize the representation of <a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">Linked Data</a>
+ in JSON, this specification outlines a common JSON representation format for
+ expressing directed graphs; mixing both Linked Data and non-Linked Data in
+ a single document.</p>
+</section><section rel="bibo:chapter" resource="#sotd" typeof="bibo:Chapter" id="sotd" class="introductory"><h2>Status of This Document</h2>
+ <p>
+ This specification was published by the <a href="http://www.w3.org/2011/rdf-wg/">RDF Working Group</a>.
+ It is not a W3C Standard nor is it on the W3C Standards Track.
+
+ Please note that under the
+ <a href="https://www.w3.org/community/about/agreements/final/">W3C Community Final Specification Agreement (FSA)</a>
+ other conditions apply.
+
+ Learn more about
+ <a href="http://www.w3.org/community/">W3C Community and Business Groups</a>.
+ </p>
+
+ <p>This document has been under development for over 25 months in the
+ JSON for Linking Data Community Group. The document has recently been
+ transferred to the RDF Working Group for review, improvement, and publication.
+ The specification has undergone significant development, review, and changes
+ during the course of the last 25 months.</p>
+
+ <p>There are several independent
+ <a href="http://json-ld.org/#impl">interoperable implementations</a> of
+ this specification. There is a
+ <a href="https://github.com/json-ld/json-ld.org/tree/master/test-suite">fairly complete test suite</a>
+ and a <a href="http://json-ld.org/playground/">live JSON-LD editor</a>
+ that is capable of demonstrating the features described in
+ this document. While development on implementations, the test suite
+ and the live editor will continue, they are believed to be mature enough
+ to be integrated into a non-production system at this point in time with
+ the expectation that they could be used in a production system within the
+ next year.</p>
+
+ <p>There are a number of ways that one may participate in the development of
+ this specification:</p>
+
+ <ul>
+ <li>If you want to make sure that your feedback is formally addressed by
+ the RDF Working Group, you should send it to public-rdf-comments:
+ <a href="http://lists.w3.org/Archives/Public/public-rdf-comments/">public-rdf-comments@w3.org</a></li>
+
+ <li>Ad-hoc technical discussion primarily occurs on the public community mailing list:
+ <a href="http://lists.w3.org/Archives/Public/public-linked-json/">public-linked-json@w3.org</a></li>
+
+ <li><a href="http://json-ld.org/minutes/">Public JSON-LD Community Group teleconferences</a>
+ are held on Tuesdays at 1500UTC every week.</li>
+
+ <li>RDF Working Group teleconferences are held on Wednesdays at 1500UTC
+ every week. Participation is limited to RDF Working Group members.</li>
+
+ <li>Specification bugs and issues should be reported in the
+ <a href="https://github.com/json-ld/json-ld.org/issues">issue tracker</a>
+ if you do not want to send an e-mail to the public-rdf-comments mailing
+ list.</li>
+
+ <li><a href="https://github.com/json-ld/json-ld.org/tree/master/spec">Source code</a>
+ for the specification can be found on Github.</li>
+
+ <li>The <a href="http://webchat.freenode.net/?channels=json-ld">#json-ld</a>
+ IRC channel is available for real-time discussion on irc.freenode.net.</li>
+ </ul>
+
+</section><section id="toc"><h2 class="introductory">Table of Contents</h2><ul class="toc"><li class="tocline"><a class="tocxref" href="#introduction"><span class="secno">1. </span>Introduction</a><ul class="toc"><li class="tocline"><a class="tocxref" href="#how-to-read-this-document"><span class="secno">1.1 </span>How to Read this Document</a></li></ul></li><li class="tocline"><a class="tocxref" href="#design-goals-and-rationale"><span class="secno">2. </span>Design Goals and Rationale</a></li><li class="tocline"><a class="tocxref" href="#terminology"><span class="secno">3. </span>Terminology</a><ul class="toc"><li class="tocline"><a class="tocxref" href="#general-terminology"><span class="secno">3.1 </span>General Terminology</a></li><li class="tocline"><a class="tocxref" href="#syntax-tokens-and-keywords"><span class="secno">3.2 </span>Syntax Tokens and Keywords</a></li></ul></li><li class="tocline"><a class="tocxref" href="#conformance"><span class="secno">4. </span>Conformance</a></li><li class="tocline"><a class="tocxref" href="#basic-concepts"><span class="secno">5. </span>Basic Concepts</a><ul class="toc"><li class="tocline"><a class="tocxref" href="#the-context"><span class="secno">5.1 </span>The Context</a></li><li class="tocline"><a class="tocxref" href="#iris"><span class="secno">5.2 </span>IRIs</a></li><li class="tocline"><a class="tocxref" href="#node-identifiers"><span class="secno">5.3 </span>Node Identifiers</a></li><li class="tocline"><a class="tocxref" href="#specifying-the-type"><span class="secno">5.4 </span>Specifying the Type</a></li></ul></li><li class="tocline"><a class="tocxref" href="#advanced-concepts"><span class="secno">6. </span>Advanced Concepts</a><ul class="toc"><li class="tocline"><a class="tocxref" href="#compact-iris"><span class="secno">6.1 </span>Compact IRIs</a></li><li class="tocline"><a class="tocxref" href="#typed-values"><span class="secno">6.2 </span>Typed Values</a></li><li class="tocline"><a class="tocxref" href="#type-coercion"><span class="secno">6.3 </span>Type Coercion</a></li><li class="tocline"><a class="tocxref" href="#advanced-context-usage"><span class="secno">6.4 </span>Advanced Context Usage</a></li><li class="tocline"><a class="tocxref" href="#interpreting-json-as-json-ld"><span class="secno">6.5 </span>Interpreting JSON as JSON-LD</a></li><li class="tocline"><a class="tocxref" href="#string-internationalization"><span class="secno">6.6 </span>String Internationalization</a></li><li class="tocline"><a class="tocxref" href="#overriding-vocab"><span class="secno">6.7 </span>Overriding @vocab</a></li><li class="tocline"><a class="tocxref" href="#property-generators"><span class="secno">6.8 </span>Property Generators</a></li><li class="tocline"><a class="tocxref" href="#iri-expansion-within-a-context"><span class="secno">6.9 </span><abbr title="Internationalized Resource Identifier">IRI</abbr> Expansion Within a Context</a></li><li class="tocline"><a class="tocxref" href="#sets-and-lists"><span class="secno">6.10 </span>Sets and Lists</a></li><li class="tocline"><a class="tocxref" href="#embedding"><span class="secno">6.11 </span>Embedding</a></li><li class="tocline"><a class="tocxref" href="#named-graphs"><span class="secno">6.12 </span>Named Graphs</a></li><li class="tocline"><a class="tocxref" href="#identifying-blank-nodes"><span class="secno">6.13 </span>Identifying Blank Nodes</a></li><li class="tocline"><a class="tocxref" href="#aliasing-keywords"><span class="secno">6.14 </span>Aliasing Keywords</a></li><li class="tocline"><a class="tocxref" href="#expanded-document-form"><span class="secno">6.15 </span>Expanded Document Form</a></li><li class="tocline"><a class="tocxref" href="#compact-document-form"><span class="secno">6.16 </span>Compact Document Form</a></li><li class="tocline"><a class="tocxref" href="#data-indexing"><span class="secno">6.17 </span>Data Indexing</a></li></ul></li><li class="tocline"><a class="tocxref" href="#data-model"><span class="secno">A. </span>Data Model</a></li><li class="tocline"><a class="tocxref" href="#json-ld-grammar"><span class="secno">B. </span>JSON-LD Grammar</a><ul class="toc"><li class="tocline"><a class="tocxref" href="#grammar-node-object"><span class="secno">B.1 </span>Node Object</a></li><li class="tocline"><a class="tocxref" href="#grammar-term-reference"><span class="secno">B.2 </span>Term</a></li><li class="tocline"><a class="tocxref" href="#grammar-language-map"><span class="secno">B.3 </span>Language Map</a></li><li class="tocline"><a class="tocxref" href="#grammar-index-map"><span class="secno">B.4 </span>Index Map</a></li><li class="tocline"><a class="tocxref" href="#grammar-expanded-values"><span class="secno">B.5 </span>Expanded Values</a></li><li class="tocline"><a class="tocxref" href="#grammar-set-list"><span class="secno">B.6 </span>List and Set Values</a></li><li class="tocline"><a class="tocxref" href="#grammar-context"><span class="secno">B.7 </span>Context Definition</a></li></ul></li><li class="tocline"><a class="tocxref" href="#relationship-to-rdf"><span class="secno">C. </span>Relationship to RDF</a></li><li class="tocline"><a class="tocxref" href="#relationship-to-other-linked-data-formats"><span class="secno">D. </span>Relationship to Other Linked Data Formats</a><ul class="toc"><li class="tocline"><a class="tocxref" href="#turtle"><span class="secno">D.1 </span>Turtle</a><ul class="toc"><li class="tocline"><a class="tocxref" href="#prefix-definitions"><span class="secno">D.1.1 </span>Prefix definitions</a></li><li class="tocline"><a class="tocxref" href="#embedding-1"><span class="secno">D.1.2 </span>Embedding</a></li><li class="tocline"><a class="tocxref" href="#lists"><span class="secno">D.1.3 </span>Lists</a></li></ul></li><li class="tocline"><a class="tocxref" href="#rdfa"><span class="secno">D.2 </span>RDFa</a></li><li class="tocline"><a class="tocxref" href="#microformats"><span class="secno">D.3 </span>Microformats</a></li><li class="tocline"><a class="tocxref" href="#microdata"><span class="secno">D.4 </span>Microdata</a></li></ul></li><li class="tocline"><a class="tocxref" href="#iana-considerations"><span class="secno">E. </span>IANA Considerations</a></li><li class="tocline"><a class="tocxref" href="#acknowledgements"><span class="secno">F. </span>Acknowledgements</a></li><li class="tocline"><a class="tocxref" href="#references"><span class="secno">G. </span>References</a><ul class="toc"><li class="tocline"><a class="tocxref" href="#normative-references"><span class="secno">G.1 </span>Normative references</a></li><li class="tocline"><a class="tocxref" href="#informative-references"><span class="secno">G.2 </span>Informative references</a></li></ul></li></ul></section>
+
+
+
+<section id="introduction" class="informative">
+ <!--OddPage--><h2><span class="secno">1. </span>Introduction</h2><p><em>This section is non-normative.</em></p>
+
+ <p><dfn id="dfn-linked-data" title="linked-data">Linked Data</dfn> is a technique for creating a network
+ of inter-connected data across different documents and Web sites. In general,
+ Linked Data has four properties: 1) it uses <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a>
+ to name things; 2) it uses HTTP <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a>
+ for those names; 3) the name <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a>, when dereferenced,
+ provide more information about the name; and 4) the data expresses links
+ to data on other Web sites. These properties allow data published on the Web
+ to work much like Web pages do today. One can start at one piece of Linked Data,
+ and follow the links to other pieces of data that are hosted on different
+ sites across the Web.</p>
+
+ <p>JSON-LD is designed as a lightweight syntax to express <a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">Linked Data</a> in
+ JSON [<cite><a href="#bib-RFC4627" class="bibref">RFC4627</a></cite>]. It is primarily intended to be a way to use Linked Data in
+ Web-based programming environments. It is also useful when building interoperable
+ Web services and when storing Linked Data in JSON-based storage engines. Since
+ JSON-LD is 100% compatible with JSON the large number of JSON parsers and libraries
+ available today can be reused. Additionally to all the features JSON provides,
+ JSON-LD introduces:</p>
+
+ <ul>
+ <li>a universal identifier mechanism for <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON objects</a>
+ via the use of <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a>,</li>
+ <li>a way to disambiguate the keys used between multiple JSON documents
+ by mapping them to <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a> via a <a href="#dfn-context" title="context" class="tref internalDFN">context</a>,</li>
+ <li>a mechanism in which a value in a <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a> may refer
+ to a <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a> on a different site on the Web,</li>
+ <li>the ability to express the language associated with a <a href="#dfn-string" title="string" class="tref internalDFN">string</a></li>
+ <li>a way to associate datatypes with values such as dates, times, weights,
+ and distances,</li>
+ <li>and a facility to express one or more directed graphs, such as a social
+ network, in a single document.</li>
+ </ul>
+
+ <p>Developers that require any of the facilities listed above or need to serialize
+ an RDF graph or dataset [<cite><a href="#bib-RDF-CONCEPTS" class="bibref">RDF-CONCEPTS</a></cite>] in a JSON-based syntax will find
+ JSON-LD of interest. The syntax is designed to not disturb already deployed
+ systems running on JSON, but provide a smooth upgrade path from JSON to
+ JSON-LD.</p>
+
+ <section id="how-to-read-this-document">
+ <h3><span class="secno">1.1 </span>How to Read this Document</h3><p><em>This section is non-normative.</em></p>
+
+ <p>This document is a detailed specification for a serialization of Linked
+ Data in JSON. The document is primarily intended for the following audiences:</p>
+
+ <ul>
+ <li>Software developers that want to encode Linked Data in a variety of
+ programming languages that can use JSON.</li>
+ <li>Software developers that want to understand the design decisions and
+ language syntax for JSON-LD.</li>
+ <li>Software developers that want to implement processors and APIs for
+ JSON-LD.</li>
+ </ul>
+
+ <p>This specification does not describe the programming interfaces for the
+ JSON-LD Syntax. The specification that describes the programming interfaces
+ for JSON-LD documents is the JSON-LD Application Programming Interface
+ [<cite><a href="#bib-JSON-LD-API" class="bibref">JSON-LD-API</a></cite>].</p>
+
+ <p>To understand the basics in this specification you must first be familiar with
+ JSON, which is detailed in [<cite><a href="#bib-RFC4627" class="bibref">RFC4627</a></cite>].</p>
+ </section>
+</section>
+
+<section id="design-goals-and-rationale" class="informative">
+ <!--OddPage--><h2><span class="secno">2. </span>Design Goals and Rationale</h2><p><em>This section is non-normative.</em></p>
+
+ <p>A number of design goals were established before the creation of this
+ markup language:</p>
+
+ <dl>
+ <dt>Simplicity</dt>
+ <dd>No extra processors or software libraries should be necessary to use JSON-LD
+ in its most basic form. The language will provide developers with a very easy
+ learning curve. Developers only need to know JSON and two
+ <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keywords</a> (<code>@context</code>
+ and <code>@id</code>) to use the basic functionality in JSON-LD.</dd>
+ <dt>Compatibility</dt>
+ <dd>The JSON-LD markup must be 100% compatible with JSON. This ensures that
+ all of the standard JSON libraries work seamlessly with JSON-LD documents.</dd>
+ <dt>Expressiveness</dt>
+ <dd>The syntax must be able to express directed graphs, which have been proven
+ to be able to express almost every real world data model.</dd>
+ <dt>Terseness</dt>
+ <dd>The JSON-LD syntax must be very terse and human readable, requiring as
+ little effort as possible from the developer.</dd>
+ <dt>Zero Edits, most of the time</dt>
+ <dd>JSON-LD must make the transition to JSON-LD as simple as possible. In many cases,
+ zero edits to the JSON document and the addition of one line to the HTTP response
+ should suffice (see <a href="#referencing-contexts-from-json-documents"></a>).
+ This allows organizations that have
+ already deployed large JSON-based infrastructure to use JSON-LD's features
+ in a way that is not disruptive to their day-to-day operations and is
+ transparent to their current customers. However, there are times where
+ mapping JSON to a graph representation is more complex than a simple one-line
+ change. In these instances, rather than extending JSON-LD to support an
+ esoteric use case, we chose not to support the use case. While Zero Edits is
+ a design goal, it is not always possible without adding great complexity
+ to the language. We should focus on simplicity when possible.</dd>
+ </dl>
+</section>
+
+<section id="terminology" class="normative">
+<!--OddPage--><h2><span class="secno">3. </span>Terminology</h2>
+
+ <section id="general-terminology">
+ <h3><span class="secno">3.1 </span>General Terminology</h3>
+
+ <p>This document uses the following terms as defined in JSON [<cite><a href="#bib-RFC4627" class="bibref">RFC4627</a></cite>]. Refer
+ to the <em>JSON Grammar</em> section in [<cite><a href="#bib-RFC4627" class="bibref">RFC4627</a></cite>] for formal definitions.</p>
+
+ <dl>
+ <dt><dfn id="dfn-json-object" title="json-object">JSON object</dfn></dt><dd>
+ An object structure is represented as a pair of curly brackets
+ surrounding zero or more key-value pairs. A key is a
+ <a href="#dfn-string" title="string" class="tref internalDFN">string</a>. A single colon comes after each key, separating the
+ key from the value. A single comma separates a value from a following
+ key.
+ </dd>
+ <dt><dfn id="dfn-array" title="array">array</dfn></dt>
+ <dd>
+ An array structure is represented as square brackets surrounding zero
+ or more values. Values are separated by commas.
+ In JSON, an array is an <em>ordered</em> sequence of zero or more values.
+ While JSON-LD uses the same array representation as JSON,
+ the collection is <em>unordered</em> by default. While order is
+ preserved in regular JSON arrays, it is not in regular JSON-LD arrays
+ unless specific markup is provided (see <a class="sec-ref" href="#sets-and-lists"><span class="secno">6.10</span> <span class="sec-title">Sets and Lists</span></a>).</dd>
+ <dt><dfn id="dfn-string" title="string">string</dfn></dt><dd>
+ A string is a sequence of zero or more Unicode characters,
+ wrapped in double quotes, using backslash escapes (if necessary). A
+ character is represented as a single character string.</dd>
+ <dt><dfn id="dfn-number" title="number">number</dfn></dt>
+ <dd>
+ A number is similar to that used in most programming languages, except
+ that the octal and hexadecimal formats are not used and that leading
+ zeros are not allowed.</dd>
+ <dt><dfn id="dfn-true" title="true">true</dfn> and <dfn id="dfn-false" title="false">false</dfn></dt><dd>
+ Values that are used to express one of two possible boolean states.</dd>
+ <dt><dfn id="dfn-null" title="null">null</dfn></dt>
+ <dd>The <a href="#dfn-null" title="null" class="tref internalDFN">null</a> value, which is typically used to clear or forget
+ data. For example, A key-value pair in the
+ <code>@context</code> where the value is <a href="#dfn-null" title="null" class="tref internalDFN">null</a> explicitly
+ decouples a <a href="#dfn-term" title="term" class="tref internalDFN">term</a>'s association with an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>.
+ A key-value pair in the body of a JSON-LD document whose
+ value is <a href="#dfn-null" title="null" class="tref internalDFN">null</a> has the same meaning as if the key-value pair
+ was not defined. If <code>@value</code>, <code>@list</code>, or
+ <code>@set</code> is set to <a href="#dfn-null" title="null" class="tref internalDFN">null</a> in expanded form, then
+ the entire <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a> is ignored.</dd>
+ </dl>
+ </section>
+
+ <section id="syntax-tokens-and-keywords">
+ <h3><span class="secno">3.2 </span>Syntax Tokens and Keywords</h3>
+
+ <p>JSON-LD specifies a number of syntax tokens and <dfn id="dfn-keyword" title="keyword">keywords</dfn>
+ that are a core part of the language:</p>
+
+ <dl>
+ <dt><code>@context</code></dt>
+ <dd>Used to define the short-hand names that are used throughout a JSON-LD
+ document. These short-hand names are called <a href="#dfn-term" title="term" class="tref internalDFN">terms</a> and help
+ developers to express specific identifiers in a compact manner. The
+ <code>@context</code> keyword is described in detail in the section titled
+ <a class="sec-ref" href="#the-context"><span class="secno">5.1</span> <span class="sec-title">The Context</span></a>.</dd>
+ <dt><code>@id</code></dt>
+ <dd>Used to uniquely identify <em>things</em> that are being described in the document.
+ This keyword is described in <a class="sec-ref" href="#node-identifiers"><span class="secno">5.3</span> <span class="sec-title">Node Identifiers</span></a>.</dd>
+ <dt><code>@value</code></dt>
+ <dd>Used to specify the data that is associated with a particular
+ <a href="#dfn-property" title="property" class="tref internalDFN">property</a> in the graph. This keyword is described in
+ <a class="sec-ref" href="#string-internationalization"><span class="secno">6.6</span> <span class="sec-title">String Internationalization</span></a> and
+ <a class="sec-ref" href="#typed-values"><span class="secno">6.2</span> <span class="sec-title">Typed Values</span></a>.</dd>
+ <dt><code>@language</code></dt>
+ <dd>Used to specify the native language for a particular value or the default
+ language of a JSON-LD document. This keyword is described in the section titled
+ <a class="sec-ref" href="#string-internationalization"><span class="secno">6.6</span> <span class="sec-title">String Internationalization</span></a>.</dd>
+ <dt><code>@type</code></dt>
+ <dd>Used to set the data type of a <a href="#dfn-node" title="node" class="tref internalDFN">node</a> or
+ <a href="#dfn-typed-value" title="typed-value" class="tref internalDFN">typed value</a>. This keyword is described in the section titled
+ <a class="sec-ref" href="#typed-values"><span class="secno">6.2</span> <span class="sec-title">Typed Values</span></a>.</dd>
+ <dt><code>@container</code></dt>
+ <dd>Used to set the default container type for a <a href="#dfn-term" title="term" class="tref internalDFN">term</a>.
+ This keyword is described in the section titled <a class="sec-ref" href="#sets-and-lists"><span class="secno">6.10</span> <span class="sec-title">Sets and Lists</span></a>.</dd>
+ <dt><code>@list</code></dt>
+ <dd>Used to express an ordered set of data.
+ This keyword is described in the section titled <a class="sec-ref" href="#sets-and-lists"><span class="secno">6.10</span> <span class="sec-title">Sets and Lists</span></a>.</dd>
+ <dt><code>@set</code></dt>
+ <dd>Used to express an unordered set of data and to ensure that values are always
+ represented as arrays. This keyword is described in the section titled
+ <a class="sec-ref" href="#sets-and-lists"><span class="secno">6.10</span> <span class="sec-title">Sets and Lists</span></a>.</dd>
+ <dt><code>@index</code></dt>
+ <dd>Used to specify that a container is used to index information and
+ that processing should continue deeper into a JSON data structure.
+ This keyword is described in the section titled
+ <a class="sec-ref" href="#data-indexing"><span class="secno">6.17</span> <span class="sec-title">Data Indexing</span></a>.</dd>
+ <dt><code>@vocab</code></dt>
+ <dd>Used to expand properties and values in <code>@type</code> with a common prefix
+ <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>. This keyword is described in section <a class="sec-ref" href="#iris"><span class="secno">5.2</span> <span class="sec-title">IRIs</span></a>.</dd>
+ <dt><code>@graph</code></dt><dd>Used to explicitly label a <a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">JSON-LD graph</a>.
+ This keyword is described in <a class="sec-ref" href="#named-graphs"><span class="secno">6.12</span> <span class="sec-title">Named Graphs</span></a>.</dd>
+ <dt><code>:</code></dt>
+ <dd>The separator for JSON keys and values that use
+ <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact IRIs</a>.</dd>
+ </dl>
+
+ <p>For the avoidance of doubt, all keys, <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keywords</a>,
+ and values in JSON-LD are case-sensitive.</p>
+ </section>
+</section>
+
+<section id="conformance" class="normative">
+ <!--OddPage--><h2><span class="secno">4. </span>Conformance</h2>
+
+ <p>This specification describes the conformance criteria for JSON-LD documents.
+ This criteria is relevant to authors and authoring tool implementers.</p>
+
+ <p>A <a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">JSON-LD document</a> complies with this specification if it follows
+ the normative statements in section <a class="sec-ref" href="#json-ld-grammar"><span class="secno">B.</span> <span class="sec-title">JSON-LD Grammar</span></a>. JSON documents
+ can be interpreted as JSON-LD by following the normative statements in section
+ <a href="#referencing-contexts-from-json-documents"></a>. For convenience, normative
+ statements for documents are often phrased as statements on the properties of the document.</p>
+
+ <p>The key words <em title="must" class="rfc2119">must</em>, <em title="must not" class="rfc2119">must not</em>, <em title="required" class="rfc2119">required</em>, <em title="shall" class="rfc2119">shall</em>, <em title="shall not" class="rfc2119">shall not</em>, <em title="should" class="rfc2119">should</em>, <em title="should not" class="rfc2119">should not</em>,
+ <em title="recommended" class="rfc2119">recommended</em>, <em title="not recommended" class="rfc2119">not recommended</em>, <em title="may" class="rfc2119">may</em>, and <em title="optional" class="rfc2119">optional</em> in this specification have the
+ meaning defined in [<cite><a href="#bib-RFC2119" class="bibref">RFC2119</a></cite>].</p>
+</section>
+
+<section id="basic-concepts" class="normative">
+ <!--OddPage--><h2><span class="secno">5. </span>Basic Concepts</h2>
+
+ <p>JSON [<cite><a href="#bib-RFC4627" class="bibref">RFC4627</a></cite>] is a lightweight, language-independent data-interchange format.
+ It is easy to parse and easy to generate. However, it is difficult to integrate JSON
+ from different sources as the data has just local meaning. Furthermore, JSON has no
+ built-in support for hyperlinks - a fundamental building block on the Web. Let's look
+ at an example that we will be using for the rest of this section:</p>
+
+ <div class="example"><div class="example-title"><span>Example 1</span>: Sample JSON document</div><pre class="example">{
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/",
+ "image": "http://manu.sporny.org/images/manu.png"
+}</pre></div>
+
+ <p>It's obvious for humans that the data is about a person whose name is "Manu Sporny"
+ and that the <code>homepage</code> property contains the URL of that person's homepage.
+ A machine doesn't have such an intuitive understanding and sometimes,
+ even for humans, it is difficult to resolve ambiguities in such representations. This problem
+ can be solved by using unambiguous identifiers to denote the different concepts instead of
+ <a href="#dfn-term" title="term" class="tref internalDFN">terms</a> such as "name", "homepage", etc.</p>
+
+ <p><a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">Linked Data</a>, and the Web in general, uses <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a>
+ (Internationalized Resource Identifiers as described in [<cite><a href="#bib-RFC3987" class="bibref">RFC3987</a></cite>]) for unambiguous
+ identification. The idea is to assign <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a> to something that may
+ be of use to other developers and that it is useful to give them an unambiguous identifier.
+ That is, it is useful for <a href="#dfn-term" title="term" class="tref internalDFN">terms</a> to expand to <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a>
+ so that developers don't accidentally step on each other's terms. Furthermore, developers and
+ machines are able to use this <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> (by using a web browser, for instance) to go to
+ the term and get a definition of what the term means.</p>
+
+ <p>Leveraging the well-known <a href="http://schema.org/">schema.org vocabulary</a>,
+ the example above could be unambiguously expressed as follows:</p>
+
+ <div class="example"><div class="example-title"><span>Example 2</span>: Sample JSON-LD document using full IRIs instead of terms</div><pre class="example">{
+ "<span class="diff">http://schema.org/name</span>": "Manu Sporny",
+ "<span class="diff">http://schema.org/url</span>": <span class="diff">{ "@id": </span>"http://manu.sporny.org/" <span class="diff">}</span>,
+ "<span class="diff">http://schema.org/image</span>": <span class="diff">{ "@id": </span>"http://manu.sporny.org/images/manu.png" <span class="diff">}</span>
+}</pre></div>
+
+ <p>In the example above, every property is unambiguously identified by an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> and all values
+ representing <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a> are explicitly marked as such by the
+ <code>@id</code> <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a>. While this is a valid JSON-LD
+ document that is very specific about its data, the document is also overly verbose and difficult
+ to work with for human developers. To address this issue, JSON-LD introduces the notion
+ of a <a href="#dfn-context" title="context" class="tref internalDFN">context</a> as described in the next section.</p>
+
+ <section id="the-context">
+ <h3><span class="secno">5.1 </span>The Context</h3>
+
+ <p>Simply speaking, a <dfn id="dfn-context" title="context">context</dfn> is used to map <a href="#dfn-term" title="term" class="tref internalDFN">terms</a>,
+ i.e., <a href="#dfn-property" title="property" class="tref internalDFN">properties</a> with associated values, to
+ <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a>. <a href="#dfn-term" title="term" class="tref internalDFN">Terms</a> are case sensitive
+ and any valid <a href="#dfn-string" title="string" class="tref internalDFN">string</a> that is not a reserved JSON-LD <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a>
+ can be used as a <a href="#dfn-term" title="term" class="tref internalDFN">term</a>.</p>
+
+ <p>For the sample document in the previous section, a <a href="#dfn-context" title="context" class="tref internalDFN">context</a> would
+ look something like this:</p>
+
+ <div class="example"><div class="example-title"><span>Example 3</span>: Context for the sample document in the previous section</div><pre class="example">{
+ <span class="diff">"@context":
+ {
+ "name": "http://schema.org/name",
+ "image": {
+ "@id": "http://schema.org/image",
+ "@type": "@id"
+ },
+ "homepage": {
+ "@id": "http://schema.org/url",
+ "@type": "@id"
+ }
+ }</span>
+}</pre></div>
+
+ <p>As the <a href="#dfn-context" title="context" class="tref internalDFN">context</a> above shows, the value of a <dfn id="dfn-term-definition" title="term-definition">term definition</dfn> can
+ either be a simple string, mapping the <a href="#dfn-term" title="term" class="tref internalDFN">term</a> to an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>,
+ or a <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a>.</p>
+
+ <p>When a <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a> is
+ associated with a term, it is called an <a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">expanded term definition</a>.
+ <dfn id="dfn-expanded-term-definition" title="expanded-term-definition">Expanded term definitions</dfn> may
+ be used to associate <a href="#type-coercion">type</a> or
+ <a href="#string-internationalization">language information</a> with a
+ term.
+ The example above specifies that the values of <code>image</code> and
+ <code>homepage</code> terms are <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a>.
+ They also allow terms to be used for <a href="#data-indexing">index maps</a>
+ and to specify whether <a href="#dfn-array" title="array" class="tref internalDFN">array</a> values are to be
+ interpreted as <a href="#sets-and-lists">sets or lists</a>.
+ <a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">Expanded term definitions</a> may
+ be defined using <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute</a> or
+ <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact IRIs</a> as keys, which is
+ mainly used to associate type or language information with an
+ <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute</a> or <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact <abbr title="Internationalized Resource Identifier">IRI</abbr></a>.</p>
+
+ <p><a href="#dfn-context" title="context" class="tref internalDFN">Contexts</a> can either be directly embedded
+ into the document or be referenced. Assuming the context document in the previous
+ example can be retrieved at <code>http://json-ld.org/contexts/person.jsonld</code>,
+ it can be referenced by adding a single line and allows a JSON-LD document to
+ be expressed much more concisely as shown in the example below:</p>
+
+ <div class="example"><div class="example-title"><span>Example 4</span>: Referencing a JSON-LD context</div><pre class="example">{
+ <span class="diff">"@context": "http://json-ld.org/contexts/person.jsonld",</span>
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/",
+ "image": "http://manu.sporny.org/images/manu.png"
+}</pre></div>
+
+ <p>The referenced context not only specifies how the terms map to
+ <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a> in the Schema.org vocabulary but also specifies that
+ the values of the <code>homepage</code> and <code>image</code> property
+ can be interpreted as an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> (<code>"@type": "@id"</code>,
+ see section <a class="sec-ref" href="#iris"><span class="secno">5.2</span> <span class="sec-title">IRIs</span></a> for more details). This information gives the
+ data global context and allows developers to re-use each other's data
+ without having to agree to how their data will interoperate on a
+ site-by-site basis. External JSON-LD context documents may contain extra
+ information located outside of the <code>@context</code> key, such as
+ documentation about the <a href="#dfn-term" title="term" class="tref internalDFN">terms</a> declared in the
+ document. Information contained outside of the <code>@context</code> value
+ is ignored when the document is used as an external JSON-LD context document.</p>
+
+ <p>Contexts may also be specified in-line. This has the advantage that
+ <a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">JSON-LD documents</a> can be processed
+ even in the absence of a connection to the Web.</p>
+
+ <div class="example"><div class="example-title"><span>Example 5</span>: In-line context definition</div><pre class="example">{
+ <span class="diff">"@context":
+ {
+ "name": "http://schema.org/name",
+ "image": {
+ "@id": "http://schema.org/image",
+ "@type": "@id"
+ },
+ "homepage": {
+ "@id": "http://schema.org/url",
+ "@type": "@id"
+ }
+ },</span>
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/",
+ "image": "http://manu.sporny.org/images/manu.png"
+}</pre></div>
+ </section>
+
+<section id="iris">
+ <h3><span class="secno">5.2 </span>IRIs</h3>
+
+ <p><a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a> (Internationalized Resource Identifiers
+ [<cite><a href="#bib-RFC3987" class="bibref">RFC3987</a></cite>]) are fundamental to <a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">Linked Data</a> as that is how most
+ <a href="#dfn-node" title="node" class="tref internalDFN">nodes</a> and <a href="#dfn-property" title="property" class="tref internalDFN">properties</a>
+ are identified. In JSON-LD, IRIs may be represented as an
+ <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a> or a <a href="#dfn-relative-iri" title="relative-iri" class="tref internalDFN">relative <abbr title="Internationalized Resource Identifier">IRI</abbr></a>. An
+ <dfn id="dfn-absolute-iri" title="absolute-iri">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></dfn> is defined in [<cite><a href="#bib-RFC3987" class="bibref">RFC3987</a></cite>] as containing a
+ <em>scheme</em> along with <em>path</em> and optional <em>query</em> and
+ <em>fragment</em> segments. A <dfn id="dfn-relative-iri" title="relative-iri">relative <abbr title="Internationalized Resource Identifier">IRI</abbr></dfn> is an <abbr title="Internationalized Resource Identifier">IRI</abbr>
+ that is relative to some other <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a>.
+ In JSON-LD all <a href="#dfn-relative-iri" title="relative-iri" class="tref internalDFN">relative IRIs</a> are resolved
+ relative to the <dfn id="dfn-base-iri" title="base-iri">base <abbr title="Internationalized Resource Identifier">IRI</abbr></dfn> associated with the document, which
+ is typically the directory path containing the document.</p>
+
+ <p><a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">IRIs</a> can be expressed directly in the key
+ position like so:</p>
+
+ <div class="example"><div class="example-title"><span>Example 6</span>: IRI as a key</div><pre class="example">{
+...
+ "<span class="diff">http://schema.org/name</span>": "Manu Sporny",
+...
+}</pre></div>
+
+ <p>In the example above, the key <code>http://schema.org/name</code>
+ is interpreted as an <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a> because it contains a colon
+ (<code>:</code>) and the "http" <a href="#dfn-prefix" title="prefix" class="tref internalDFN">prefix</a> does not exist in
+ the context.</p>
+
+ <p>Term-to-<abbr title="Internationalized Resource Identifier">IRI</abbr> expansion occurs if the key matches a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> defined
+ within the <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a>:</p>
+
+ <div class="example"><div class="example-title"><span>Example 7</span>: Term expansion from context definition</div><pre class="example">{
+ "<span class="diff">@context</span>":
+ {
+ "<span class="diff">name</span>": "<span class="diff">http://schema.org/name</span>"
+...
+ },
+ "<span class="diff">name</span>": "Manu Sporny",
+ "status": "trollin'",
+...
+}</pre></div>
+
+ <p>JSON keys that do not expand to an absolute <abbr title="Internationalized Resource Identifier">IRI</abbr> are ignored, or removed
+ in some cases, by the [<cite><a href="#bib-JSON-LD-API" class="bibref">JSON-LD-API</a></cite>]. However, JSON keys that do not include
+ a mapping in the <a href="#dfn-context" title="context" class="tref internalDFN">context</a> are still considered valid expressions
+ in JSON-LD documents—the keys just don't expand to unambiguous identifiers.</p>
+
+ <p>At times, all properties and types may come from the same vocabulary. JSON-LD's
+ <code>@vocab</code> keyword allows an author to set a common prefix to be used
+ for all properties and types that do not match a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> or are neither
+ a <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact <abbr title="Internationalized Resource Identifier">IRI</abbr></a> nor an <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a> (i.e., they do
+ not contain a colon).</p>
+
+ <div class="example"><div class="example-title"><span>Example 8</span>: Using a common vocabulary prefix</div><pre class="example">{
+ <span class="diff">"@context": {
+ "@vocab": "http://schema.org/"
+ },</span>
+ "@type": <span class="diff">"Person"</span>,
+ <span class="diff">"name"</span>: "Manu Sporny",
+}</pre></div>
+
+ <p>An <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> is generated when a <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a> is used in
+ the value position and contains an <code>@id</code> keyword:</p>
+
+ <div class="example"><div class="example-title"><span>Example 9</span>: Expanded IRI definition</div><pre class="example">{
+...
+ "homepage": { "<span class="diff">@id</span>": "http://manu.sporny.org" }
+...
+}</pre></div>
+
+ <p>Specifying a <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a> with an
+ <code>@id</code> key is used to identify that <a href="#dfn-node" title="node" class="tref internalDFN">node</a> using an
+ <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>. This facility may also be used to link to another
+ <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a> using a mechanism called
+ <a href="#dfn-embedding" title="embedding" class="tref internalDFN">embedding</a>, which is covered in the section titled
+ <a class="sec-ref" href="#embedding"><span class="secno">6.11</span> <span class="sec-title">Embedding</span></a>.</p>
+
+ <p>If type <a href="#dfn-coercion" title="coercion" class="tref internalDFN">coercion</a> rules are specified in the <code>@context</code> for
+ a particular <a href="#dfn-term" title="term" class="tref internalDFN">term</a> or property <abbr title="Internationalized Resource Identifier">IRI</abbr>, an <abbr title="Internationalized Resource Identifier">IRI</abbr> is generated:</p>
+
+ <div class="example"><div class="example-title"><span>Example 10</span>: Type coercion</div><pre class="example">{<span class="diff">
+ "@context":
+ {
+ ...
+ "homepage":
+ {
+ "@id": "http://schema.org/homepage",
+ "@type": "@id"
+ }
+ ...
+ }</span>
+...
+ "homepage": "http://manu.sporny.org/",
+...
+}</pre></div>
+
+ <p>In the example above, even though the value <code>http://manu.sporny.org/</code>
+ is expressed as a JSON <a href="#dfn-string" title="string" class="tref internalDFN">string</a>, the type <a href="#dfn-coercion" title="coercion" class="tref internalDFN">coercion</a>
+ rules will transform the value into an <abbr title="Internationalized Resource Identifier">IRI</abbr> when generating the
+ <a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">JSON-LD graph</a>. See <a class="sec-ref" href="#type-coercion"><span class="secno">6.3</span> <span class="sec-title">Type Coercion</span></a> for more
+ details about this feature.</p>
+
+ <p>In summary, <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a> can be expressed in a variety of
+ different ways in JSON-LD:</p>
+
+ <ol>
+ <li><a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a> keys that have a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> mapping in
+ the <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a> expand to an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>
+ (only applies outside of the <a href="#dfn-context-definition" title="context-definition" class="tref internalDFN">context definition</a>).</li>
+ <li>If there is a <code>@vocab</code> mapping in the active context,
+ <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a> keys without an explicit mapping
+ in the <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a> are expanded to an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>.</li>
+ <li>An <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> is generated for the <a href="#dfn-string" title="string" class="tref internalDFN">string</a> value specified using
+ <code>@id</code> or <code>@type</code>.</li>
+ <li>An <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> is generated for the <a href="#dfn-string" title="string" class="tref internalDFN">string</a> value of any key for which there
+ are <a href="#dfn-coercion" title="coercion" class="tref internalDFN">coercion</a> rules that contain a <code>@type</code> key that is
+ set to a value of <code>@id</code> or <code>@vocab</code>.</li>
+ </ol>
+</section>
+
+<section id="node-identifiers">
+ <h3><span class="secno">5.3 </span>Node Identifiers</h3>
+
+ <p>To be able to externally reference <a href="#dfn-node" title="node" class="tref internalDFN">nodes</a>
+ in a <a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">graph</a>, it is important that each <a href="#dfn-node" title="node" class="tref internalDFN">node</a> has
+ an unambiguous identifier. <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a> are a fundamental concept of
+ <a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">Linked Data</a>, and <a href="#dfn-node" title="node" class="tref internalDFN">nodes</a> should have a de-referenceable
+ identifier used to name and locate them. For <a href="#dfn-node" title="node" class="tref internalDFN">nodes</a> to be truly linked,
+ de-referencing the identifier should result in a representation of that <a href="#dfn-node" title="node" class="tref internalDFN">node</a>.
+ Associating an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> with a <a href="#dfn-node" title="node" class="tref internalDFN">node</a> tells an application that it
+ can fetch the resource associated with the <abbr title="Internationalized Resource Identifier">IRI</abbr> and get back a description of the
+ <a href="#dfn-node" title="node" class="tref internalDFN">node</a>.</p>
+
+ <p><a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">JSON-LD documents</a> may also contain descriptions
+ of other <a href="#dfn-node" title="node" class="tref internalDFN">nodes</a>, so it is necessary to be able to
+ uniquely identify each <a href="#dfn-node" title="node" class="tref internalDFN">node</a> so that the data is associated
+ with the correct <a href="#dfn-node" title="node" class="tref internalDFN">node</a> in an unambiguous way.</p>
+
+ <p>A <a href="#dfn-node" title="node" class="tref internalDFN">node</a> is identified using the <code>@id</code>
+ <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a>:</p>
+
+ <div class="example"><div class="example-title"><span>Example 11</span>: Identifying a node</div><pre class="example">{
+ "@context":
+ {
+ ...
+ "homepage":
+ {
+ "@id": "http://schema.org/homepage",
+ "@type": "@id"
+ }
+ },
+ "<span class="diff">@id</span>": "<span class="diff">http://example.org/people#joebob</span>",
+ "homepage": "http://joebob.example.com/",
+ ...
+}</pre></div>
+
+ <p>The example above contains a <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a> identified by the <abbr title="Internationalized Resource Identifier">IRI</abbr>
+ <code>http://example.org/people#joebob</code>.</p>
+</section>
+
+<section id="specifying-the-type">
+<h3><span class="secno">5.4 </span>Specifying the Type</h3>
+
+<p>The type of a particular node can be specified using the <code>@type</code>
+ <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a>. In <a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">Linked Data</a>, types are uniquely
+ identified with an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>.</p>
+
+<div class="example"><div class="example-title"><span>Example 12</span>: Specifying the type for a node</div><pre class="example">{
+...
+ "@id": "http://example.org/places#BrewEats",
+ "<span class="diff">@type</span>": "<span class="diff">http://schema.org/Restaurant</span>",
+...
+}</pre></div>
+
+<p>A node can be assigned more than one type by using an <a href="#dfn-array" title="array" class="tref internalDFN">array</a>:</p>
+
+<div class="example"><div class="example-title"><span>Example 13</span>: Specifying multiple types for a node</div><pre class="example">{
+...
+ "@id": "http://example.org/places#BrewEats",
+ "<span class="diff">@type</span>": <span class="diff">[ "http://schema.org/Restaurant", "http://schema.org/Brewery" ],</span>
+...
+}</pre></div>
+
+<p>The value of a <code>@type</code> key may also be a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> defined in the <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a>:</p>
+<div class="example"><div class="example-title"><span>Example 14</span>: Using a term to specify the type</div><pre class="example">{
+ "@context": {
+ ...
+ <span class="diff">"Restaurant": "http://schema.org/Restaurant", </span>
+ <span class="diff">"Brewery": "http://schema.org/Brewery"</span>
+ }
+ "@id": "http://example.org/places#BrewEats",
+ <span class="diff">"@type": ["Restaurant", "Brewery"]</span>,
+ ...
+}</pre></div>
+
+</section>
+</section>
+
+<section id="advanced-concepts">
+<!--OddPage--><h2><span class="secno">6. </span>Advanced Concepts</h2>
+
+<em>This section is normative.</em>
+
+<p>JSON-LD has a number of features that provide functionality above and beyond
+the core functionality described above. The following section describes this
+advanced functionality in more detail.
+</p>
+
+<section id="compact-iris">
+ <h3><span class="secno">6.1 </span>Compact IRIs</h3>
+ <p>A document on the Web that defines one or more IRIs for use as
+ <a href="#dfn-property" title="property" class="tref internalDFN">properties</a> in Linked Data is called a
+ <dfn id="dfn-vocabulary" title="vocabulary">vocabulary</dfn>.
+ <a href="#dfn-term" title="term" class="tref internalDFN">Terms</a> in <a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">Linked Data</a> documents may draw from
+ a number of different <a href="#dfn-vocabulary" title="vocabulary" class="tref internalDFN">vocabularies</a>s. At times, declaring every single <a href="#dfn-term" title="term" class="tref internalDFN">term</a>
+ that a document uses can require the developer to declare tens, if not hundreds of potential
+ vocabulary <a href="#dfn-term" title="term" class="tref internalDFN">terms</a> that are used across an
+ application. This is a concern for at least two reasons: the
+ first is the cognitive load on the developer of remembering all of the
+ <a href="#dfn-term" title="term" class="tref internalDFN">terms</a>, and the second is the serialized size of the
+ <a href="#dfn-context" title="context" class="tref internalDFN">context</a> if it is specified inline. In order to address these issues,
+ the concept of a <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact <abbr title="Internationalized Resource Identifier">IRI</abbr></a> is introduced.</p>
+ <p>
+ A <dfn id="dfn-compact-iri" title="compact-iri">compact <abbr title="Internationalized Resource Identifier">IRI</abbr></dfn> is a way of expressing an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>
+ using a <em>prefix</em> and <em>suffix</em> separated by a colon (<code>:</code>) which is
+ similar to the <cite><a href="http://www.w3.org/TR/rdfa-core/#s_curies">CURIE Syntax</a></cite>
+ in [<cite><a href="#bib-RDFA-CORE" class="bibref">RDFA-CORE</a></cite>]. The <dfn id="dfn-prefix" title="prefix">prefix</dfn> is a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> taken from the
+ <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a> and is a short string identifying a
+ particular <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> in a JSON-LD document.
+ For example, the prefix <code>foaf</code> may be used as a short
+ hand for the Friend-of-a-Friend vocabulary, which is identified using
+ the <abbr title="Internationalized Resource Identifier">IRI</abbr> <code>http://xmlns.com/foaf/0.1/</code>. A developer may append
+ any of the FOAF vocabulary terms to the end of the prefix to specify a short-hand
+ version of the <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a> for the vocabulary term. For example,
+ <code>foaf:name</code> would be expanded out to the <abbr title="Internationalized Resource Identifier">IRI</abbr>
+ <code>http://xmlns.com/foaf/0.1/name</code>. Instead of having to remember and
+ type out the entire <abbr title="Internationalized Resource Identifier">IRI</abbr>, the developer can instead use the prefix in their JSON-LD markup.
+ </p>
+
+ <p><a href="#dfn-prefix" title="prefix" class="tref internalDFN">Prefixes</a> are expanded when the form of the value
+ is a <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact <abbr title="Internationalized Resource Identifier">IRI</abbr></a> represented as a <code>prefix:suffix</code>
+ combination, and the prefix matches a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> defined within the
+ <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a>:</p>
+
+ <div class="example"><div class="example-title"><span>Example 15</span>: Prefix expansion</div><pre class="example">{
+ "<span class="diff">@context</span>":
+ {
+ "<span class="diff">foaf</span>": "<span class="diff">http://xmlns.com/foaf/0.1/</span>"
+...
+ },
+ "<span class="diff">foaf:name</span>": "Dave Longley",
+...
+}</pre></div>
+
+ <p><code>foaf:name</code> above will automatically expand out to the <abbr title="Internationalized Resource Identifier">IRI</abbr>
+ <code>http://xmlns.com/foaf/0.1/name</code>.</p>
+
+ <p>Terms are interpreted as <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact IRIs</a> if they contain at least one
+ colon and the first colon is not followed by two slashes (<code>//</code>, as in
+ <code>http://example.com</code>). To generate the full <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>,
+ the value is first split into a <em>prefix</em> and <em>suffix</em> at the first
+ occurrence of a colon (<code>:</code>). If the <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a>
+ contains a term mapping for <em>prefix</em>, an <abbr title="Internationalized Resource Identifier">IRI</abbr> is generated by
+ prepending the mapped <em>prefix</em> to the (possibly empty) <em>suffix</em>
+ using textual concatenation. If no prefix mapping is defined, the value is interpreted
+ as an <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a>. If the prefix is an underscore
+ (<code>_</code>), the <abbr title="Internationalized Resource Identifier">IRI</abbr> remains unchanged.
+ </p>
+ <p>Consider the following example:</p>
+ <div class="example"><div class="example-title"><span>Example 16</span>: Compact IRIs</div><pre class="example">{
+ "@context":
+ {
+ <span class="diff">"dc": "http://purl.org/dc/elements/1.1/",</span>
+ <span class="diff">"ex": "http://example.org/vocab#"</span>
+ },
+ "@id": "http://example.org/library",
+ "@type": <span class="diff">"ex:Library"</span>,
+ <span class="diff">"ex:contains"</span>:
+ {
+ "@id": "http://example.org/library/the-republic",
+ "@type": <span class="diff">"ex:Book"</span>,
+ <span class="diff">"dc:creator"</span>: "Plato",
+ <span class="diff">"dc:title"</span>: "The Republic",
+ <span class="diff">"ex:contains"</span>:
+ {
+ "@id": "http://example.org/library/the-republic#introduction",
+ "@type": <span class="diff">"ex:Chapter"</span>,
+ <span class="diff">"dc:description"</span>: "An introductory chapter on The Republic.",
+ <span class="diff">"dc:title"</span>: "The Introduction"
+ }
+ }
+}</pre></div>
+
+ <p>In this example, two different vocabularies are referred to using prefixes.
+ Those prefixes are then used as type and property values using the compact
+ <abbr title="Internationalized Resource Identifier">IRI</abbr> <code>prefix:suffix</code> notation.</p>
+
+ <p>It's also possible to use compact IRIs within the context as shown in the
+ following example:</p>
+
+ <div class="example"><div class="example-title"><span>Example 17</span>: Using vocabularies</div><pre class="example">{
+ "@context":
+ {
+ "xsd": "http://www.w3.org/2001/XMLSchema#",
+ <span class="diff">"foaf": "http://xmlns.com/foaf/0.1/"</span>,
+ <span class="diff">"foaf:homepage"</span>: { "@type": "@id" },
+ "picture": { "@id": <span class="diff">"foaf:depiction"</span>, "@type": "@id" }
+ },
+ "@id": "http://me.markus-lanthaler.com/",
+ "@type": "foaf:Person",
+ "foaf:name": "Markus Lanthaler",
+ "foaf:homepage": "http://www.markus-lanthaler.com/",
+ "picture": "http://twitter.com/account/profile_image/markuslanthaler"
+}</pre></div>
+</section>
+
+<section id="typed-values">
+<h3><span class="secno">6.2 </span>Typed Values</h3>
+
+<p>
+ A value with an associated type, also known as a
+ <a href="#dfn-typed-value" title="typed-value" class="tref internalDFN">typed value</a>, is indicated by associating a value with
+ an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> which indicates the value's type. Typed values may be
+ expressed in JSON-LD in three ways:
+</p>
+
+<ol>
+ <li>By utilizing the <code>@type</code> <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a> when defining
+ a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> within a <code>@context</code> section.</li>
+ <li>By utilizing an <a href="#dfn-expanded-typed-value" title="expanded-typed-value" class="tref internalDFN">expanded typed value</a>.</li>
+ <li>By using a native JSON type such as <a href="#dfn-number" title="number" class="tref internalDFN">number</a>, <a href="#dfn-true" title="true" class="tref internalDFN">true</a>, or <a href="#dfn-false" title="false" class="tref internalDFN">false</a>.</li>
+</ol>
+
+<p>The first example uses the <code>@type</code> keyword to associate a
+type with a particular <a href="#dfn-term" title="term" class="tref internalDFN">term</a> in the <code>@context</code>:</p>
+
+<div class="example"><div class="example-title"><span>Example 18</span>: Expanded term definition with type coercion</div><pre class="example">{
+ <span class="diff">"@context":
+ {
+ "modified":
+ {
+ "@id": "http://purl.org/dc/terms/modified",
+ "@type": "http://www.w3.org/2001/XMLSchema#dateTime"
+ }
+ },</span>
+...
+ "@id": "http://example.com/docs/1",
+ "modified": "2010-05-29T14:17:39+02:00",
+...
+}</pre></div>
+
+<p>The <em>modified</em> key's value above is automatically type coerced to a
+dateTime value because of the information specified in the
+<code>@context</code>. A JSON-LD processor will interpret the markup above
+like so:</p>
+
+<table class="example">
+<thead>
+ <tr><th>Subject</th>
+ <th>Property</th>
+ <th>Value</th>
+ <th>Value Type</th>
+</tr></thead>
+<tbody>
+<tr>
+ <td>http://example.com/docs/1</td>
+ <td>http://purl.org/dc/terms/modified</td>
+ <td>2010-05-29T14:17:39+02:00</td>
+ <td>http://www.w3.org/2001/XMLSchema#dateTime</td>
+</tr>
+</tbody>
+</table>
+
+<p>The second example uses the expanded form of setting the type information
+in the body of a JSON-LD document:</p>
+
+<div class="example"><div class="example-title"><span>Example 19</span>: Expanded value with type</div><pre class="example">{
+ "@context":
+ {
+ "modified":
+ {
+ "@id": "http://purl.org/dc/terms/modified"
+ }
+ },
+...
+ "modified":
+ <span class="diff">{
+ "@value": "2010-05-29T14:17:39+02:00",
+ "@type": "http://www.w3.org/2001/XMLSchema#dateTime"
+ }</span>
+...
+}</pre></div>
+
+<p>Both examples above would generate the value
+ <code>2010-05-29T14:17:39+02:00</code> with the type
+ <code>http://www.w3.org/2001/XMLSchema#dateTime</code>. Note that it is
+ also possible to use a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> or a <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact <abbr title="Internationalized Resource Identifier">IRI</abbr></a> to
+ express the value of a type.</p>
+
+<p>The <code>@type</code> <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a> is also used to associate a type
+ with a <a href="#dfn-node" title="node" class="tref internalDFN">node</a>. The concept of a <a href="#dfn-node-type" title="node-type" class="tref internalDFN">node type</a> and
+ a <a href="#dfn-value-type" title="value-type" class="tref internalDFN">value type</a> are different.</p>
+
+<p>Generally speaking, a
+ <dfn id="dfn-node-type" title="node-type">node type</dfn> specifies the type of thing that is being described,
+ like a person, place, event, or web page. A <dfn id="dfn-value-type" title="value-type">value type</dfn> specifies
+ the unit of measurement for a particular value, such as a date, meter,
+ or light year.</p>
+
+<div class="example"><div class="example-title"><span>Example 20</span>: Example demonstrating the context-sensitivity for @type</div><pre class="example">{
+...
+ "@id": "http://example.org/posts#TripToWestVirginia",
+ <span class="diff">"@type": "http://schema.org/BlogPosting"</span>, <--- This is a node type
+ "modified":
+ {
+ "@value": "2010-05-29T14:17:39+02:00",
+ <span class="diff">"@type": "http://www.w3.org/2001/XMLSchema#dateTime"</span> <--- This is a value type
+ }
+...
+}</pre></div>
+
+<p>The first use of <code>@type</code> associates a <a href="#dfn-node-type" title="node-type" class="tref internalDFN">node type</a>
+ (<code>http://schema.org/BlogPosting</code>) with the <a href="#dfn-node" title="node" class="tref internalDFN">node</a>,
+ which is expressed using the <code>@id</code> <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a>.
+ The second use of <code>@type</code> associates a <a href="#dfn-value-type" title="value-type" class="tref internalDFN">value type</a>
+ (<code>http://www.w3.org/2001/XMLSchema#dateTime</code>) with the
+ value expressed using the <code>@value</code> <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a>. As a
+ general rule, when <code>@value</code> and <code>@type</code> are used in
+ the same <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a>, the <code>@type</code>
+ <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a> is expressing a <a href="#dfn-value-type" title="value-type" class="tref internalDFN">value type</a>.
+ Otherwise, the <code>@type</code> <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a> is expressing a
+ <a href="#dfn-node-type" title="node-type" class="tref internalDFN">node type</a>. The markup above expresses the following data:</p>
+
+<table class="example">
+<thead>
+ <tr><th>Subject</th>
+ <th>Property</th>
+ <th>Value</th>
+ <th>Value Type</th>
+</tr></thead>
+<tbody>
+<tr>
+ <td>http://example.org/posts#TripToWestVirginia</td>
+ <td>http://www.w3.org/1999/02/22-rdf-syntax-ns#type</td>
+ <td>http://schema.org/BlogPosting</td>
+ <td style="text-align:center;">-</td>
+</tr>
+<tr>
+ <td>http://example.org/posts#TripToWestVirginia</td>
+ <td>http://purl.org/dc/terms/modified</td>
+ <td>2010-05-29T14:17:39+02:00</td>
+ <td>http://www.w3.org/2001/XMLSchema#dateTime</td>
+</tr>
+</tbody>
+</table>
+
+</section>
+
+<section id="type-coercion">
+<h3><span class="secno">6.3 </span>Type Coercion</h3>
+
+<p>JSON-LD supports the coercion of values to particular data types.
+Type <dfn id="dfn-coercion" title="coercion">coercion</dfn> allows someone deploying JSON-LD to coerce the incoming or
+outgoing values to the proper data type based on a mapping of data type <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a> to
+<a href="#dfn-term" title="term" class="tref internalDFN">terms</a>. Using type coercion, value representation is preserved without requiring
+the data type to be specified with each piece of data.</p>
+
+<p>Type coercion is specified within an <a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">expanded term definition</a>
+ using the <code>@type</code> key. The value of this key expands to an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>.
+ Alternatively, the <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keywords</a> <code>@id</code> or <code>@vocab</code> may be used
+ as value to indicate that within the body of a JSON-LD document, a <a href="#dfn-string" title="string" class="tref internalDFN">string</a> value of a
+ <a href="#dfn-term" title="term" class="tref internalDFN">term</a> coerced to <code>@id</code> or <code>@vocab</code> is to be interpreted as an
+ <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>. The difference between <code>@id</code> and <code>@vocab</code> is how values are expanded
+ to <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute IRIs</a>. <code>@vocab</code> first tries to expand the value
+ by interpreting it as <a href="#dfn-term" title="term" class="tref internalDFN">term</a>. If no matching <a href="#dfn-term" title="term" class="tref internalDFN">term</a> is found in the
+ <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a>, it tries to expand it as <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact <abbr title="Internationalized Resource Identifier">IRI</abbr></a> or <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a>
+ if there's a colon in the value; otherwise, it will expand the value using the
+ <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context's</a> vocabulary mapping, if present, or by interpreting it
+ as <a href="#dfn-relative-iri" title="relative-iri" class="tref internalDFN">relative <abbr title="Internationalized Resource Identifier">IRI</abbr></a>. Values coerced to <code>@id</code> in contrast are expanded as
+ <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact <abbr title="Internationalized Resource Identifier">IRI</abbr></a> or <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a> if a colon is present; otherwise, they are interpreted
+ as <a href="#dfn-relative-iri" title="relative-iri" class="tref internalDFN">relative <abbr title="Internationalized Resource Identifier">IRI</abbr></a>.
+
+</p><p><a href="#dfn-term" title="term" class="tref internalDFN">Terms</a> or <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact IRIs</a> used as the value of a
+ <code>@type</code> key may be defined within the same context. This means that one may specify a
+ <a href="#dfn-term" title="term" class="tref internalDFN">term</a> like <code>xsd</code> and then use <code>xsd:integer</code> within the same
+ context definition.</p>
+
+<p>The example below demonstrates how a JSON-LD author can coerce values to
+<a href="#dfn-typed-value" title="typed-value" class="tref internalDFN">typed values</a>, IRIs, and lists.</p>
+
+<div class="example"><div class="example-title"><span>Example 21</span>: Expanded term definition with types</div><pre class="example">{
+ "@context":
+ {
+ "xsd": "http://www.w3.org/2001/XMLSchema#",
+ "name": "http://xmlns.com/foaf/0.1/name",
+ "age":
+ <span class="diff">{
+ "@id": "http://xmlns.com/foaf/0.1/age",
+ "@type": "xsd:integer"
+ }</span>,
+ "homepage":
+ <span class="diff">{
+ "@id": "http://xmlns.com/foaf/0.1/homepage",
+ "@type": "@id",
+ "@container": "@list"
+ }</span>
+ },
+ "@id": "http://example.com/people#john",
+ "name": "John Smith",
+ "age": <span class="diff">"41"</span>,
+ "homepage":
+ <span class="diff">[
+ "http://personal.example.org/",
+ "http://work.example.com/jsmith/"
+ ]</span>
+}</pre></div>
+
+<p>The markup shown above would generate the following data. The data has no inherent order
+ except for the values of the <code>http://schema.org/homepage</code> property
+ which represent an ordered list.</p>
+
+<table class="example">
+<thead>
+ <tr><th>Subject</th>
+ <th>Property</th>
+ <th>Value</th>
+ <th>Value Type</th>
+</tr></thead>
+<tbody>
+<tr>
+ <td>http://example.com/people#john</td>
+ <td>http://xmlns.com/foaf/0.1/name</td>
+ <td>John Smith</td>
+ <td> </td>
+</tr>
+<tr>
+ <td>http://example.com/people#john</td>
+ <td>http://xmlns.com/foaf/0.1/age</td>
+ <td>41</td>
+ <td>http://www.w3.org/2001/XMLSchema#integer</td>
+</tr>
+<tr>
+ <td rowspan="2">http://example.com/people#john</td>
+ <td rowspan="2">http://xmlns.com/foaf/0.1/homepage</td>
+ <td>http://personal.example.org/</td>
+ <td> </td>
+</tr>
+<tr>
+ <td>http://work.example.com/jsmith/</td>
+ <td> </td>
+</tr>
+</tbody>
+</table>
+
+<p>Terms may also be defined using <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute IRIs</a> or <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact IRIs</a>.
+ This allows coercion rules to be applied to keys which are not represented as a simple <a href="#dfn-term" title="term" class="tref internalDFN">term</a>.
+ For example:</p>
+
+<div class="example"><div class="example-title"><span>Example 22</span>: Term definitions using compact and absolute IRIs</div><pre class="example">{
+ "@context":
+ {
+ "foaf": "http://xmlns.com/foaf/0.1/",
+ "<span class="diff">foaf:age</span>":
+ {
+ <span class="diff">"@id": "http://xmlns.com/foaf/0.1/age"</span>,
+ "@type": "xsd:integer"
+ },
+ "<span class="diff">http://xmlns.com/foaf/0.1/homepage</span>":
+ {
+ "@type": "@id"
+ }
+ },
+ "foaf:name": "John Smith",
+ "<span class="diff">foaf:age</span>": "41",
+ "<span class="diff">http://xmlns.com/foaf/0.1/homepage</span>":
+ [
+ "http://personal.example.org/",
+ "http://work.example.com/jsmith/"
+ ]
+}</pre></div>
+
+<p>In this case the <code>@id</code> definition in the term definition is optional, but if it does exist, the <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact <abbr title="Internationalized Resource Identifier">IRI</abbr></a>
+ or <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> is treated as a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> (not a <code>prefix:suffix</code> construct)
+ so that the actual definition of a <a href="#dfn-prefix" title="prefix" class="tref internalDFN">prefix</a> becomes unnecessary. Type coercion is performed using
+ the unexpanded value of the key if there is an exact match for the key in the <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a>.</p>
+
+<div class="note"><div class="note-title"><span>Note</span></div><p class="">Keys in the context are treated as <a href="#dfn-term" title="term" class="tref internalDFN">terms</a> for the purpose of
+ expansion and value coercion. At times, this may result in multiple representations for the same expanded <abbr title="Internationalized Resource Identifier">IRI</abbr>.
+ For example, one could specify that <code>dog</code> and <code>cat</code> both expanded to <code>http://example.com/vocab#animal</code>.
+ Doing this could be useful for establishing different type coercion or language specification rules. It also allows a <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact <abbr title="Internationalized Resource Identifier">IRI</abbr></a> (or even an
+ absolute <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>) to be defined as something else entirely. For example, one could specify that
+ the <a href="#dfn-term" title="term" class="tref internalDFN">term</a> <code>http://example.org/zoo</code> should expand to
+ <code>http://example.org/river</code>, but this usage is discouraged because it would lead to a
+ great deal of confusion among developers attempting to understand the JSON-LD document.</p></div>
+
+
+</section>
+
+<section id="advanced-context-usage">
+ <h3><span class="secno">6.4 </span>Advanced Context Usage</h3>
+
+ <p>Section <a class="sec-ref" href="#the-context"><span class="secno">5.1</span> <span class="sec-title">The Context</span></a> introduced the basics of what makes
+ JSON-LD work. This section expands on the basic principles of the
+ <a href="#dfn-context" title="context" class="tref internalDFN">context</a> and demonstrates how more advanced use cases can
+ be achieved using JSON-LD. </p>
+
+ <p>In general, contexts may be used at any time a
+ <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a> is defined. The only time that one cannot
+ express a context is inside a context definition itself. For example, a
+ <a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">JSON-LD document</a> may use more than one context at different
+ points in a document:</p>
+
+ <div class="example"><div class="example-title"><span>Example 23</span>: Using multiple contexts</div><pre class="example">[
+ {
+ <span class="diff">"@context": "http://example.org/contexts/person.jsonld",</span>
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/",
+ "depiction": "http://twitter.com/account/profile_image/manusporny"
+ },
+ {
+ <span class="diff">"@context": "http://example.org/contexts/place.jsonld",</span>
+ "name": "The Empire State Building",
+ "description": "The Empire State Building is a 102-story landmark in New York City.",
+ "geo": {
+ "latitude": "40.75",
+ "longitude": "73.98"
+ }
+ }
+]</pre></div>
+
+ <p>Duplicate context <a href="#dfn-term" title="term" class="tref internalDFN">terms</a> are overridden using a
+ last-defined-wins mechanism.</p>
+
+ <div class="example"><div class="example-title"><span>Example 24</span>: Scoped contexts within node objects</div><pre class="example">{
+ <span class="diff">"@context":
+ {
+ "name": "http://example.com/person#name",
+ "details": "http://example.com/person#details"
+ },</span>
+ "<span class="diff">name</span>": "Markus Lanthaler",
+ ...
+ "details":
+ {
+ <span class="diff">"@context": {
+ "name": "http://example.com/organization#name"
+ },</span>
+ "<span class="diff">name</span>": "Graz University of Technology"
+ }
+}</pre></div>
+
+ <p>In the example above, the <code>name</code> <a href="#dfn-term" title="term" class="tref internalDFN">term</a> is overridden
+ in the more deeply nested <code>details</code> structure. Note that this is
+ rarely a good authoring practice and is typically used when working with
+ legacy applications that depend on a specific structure of the
+ <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a>. If a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> is redefined within a
+ context, all previous rules associated with the previous definition are
+ removed. If a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> is redefined to <code>null</code>,
+ the <a href="#dfn-term" title="term" class="tref internalDFN">term</a> is effectively removed from the list of
+ <a href="#dfn-term" title="term" class="tref internalDFN">terms</a> defined in the <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a>.</p>
+
+ <p>Multiple contexts may be combined using an <a href="#dfn-array" title="array" class="tref internalDFN">array</a>, which is processed
+ in order. The set of contexts defined within a specific <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a> are
+ referred to as <dfn id="dfn-local-context" title="local-context">local contexts</dfn>. The
+ <dfn id="dfn-active-context" title="active-context">active context</dfn> refers to the accumulation of
+ <a href="#dfn-local-context" title="local-context" class="tref internalDFN">local contexts</a> that are in scope at a
+ specific point within the document. Setting a <a href="#dfn-local-context" title="local-context" class="tref internalDFN">local context</a>
+ to <code>null</code> effectively resets the <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a>
+ to an empty context. The following example specifies an external context
+ and then layers an embedded context on top of the external context:</p>
+
+ <div class="example"><div class="example-title"><span>Example 25</span>: Combining external and local contexts</div><pre class="example">{
+ <span class="diff">"@context": [
+ "http://json-ld.org/contexts/person.jsonld",
+ {
+ "pic": "http://xmlns.com/foaf/0.1/depiction"
+ }
+ ],</span>
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/",
+ <span class="diff">"pic": "http://twitter.com/account/profile_image/manusporny"</span>
+}</pre></div>
+
+ <div class="note"><div class="note-title"><span>Note</span></div><p class="">It is a best practice to put the <a href="#dfn-context" title="context" class="tref internalDFN">context</a> definition
+ at the top of the JSON-LD document.</p></div>
+
+ <div class="note"><div class="note-title"><span>Note</span></div><p class="">To avoid forward-compatibility issues,
+ <a href="#dfn-term" title="term" class="tref internalDFN">terms</a> starting with an <code>@</code> character are
+ to be avoided as they might be used as <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keywords</a>
+ in future versions of JSON-LD. Furthermore, the use of empty
+ <a href="#dfn-term" title="term" class="tref internalDFN">terms</a> (<code>""</code>) is discouraged as not all
+ programming languages are able to handle empty property names.</p></div>
+</section>
+
+<section id="interpreting-json-as-json-ld">
+ <h3><span class="secno">6.5 </span>Interpreting JSON as JSON-LD</h3>
+
+ <p>Ordinary JSON documents can be interpreted as JSON-LD by referencing a JSON-LD
+ <a href="#dfn-context" title="context" class="tref internalDFN">context</a> document in an HTTP Link Header. Doing so allows JSON to
+ be unambiguously machine-readable without requiring developers to drastically
+ change their markup and provides an upgrade path for existing infrastructure
+ without breaking existing clients that rely on the <code>application/json</code>
+ media type.</p>
+
+ <p>In order to use an external context with an ordinary JSON document, an author
+ <em title="must" class="rfc2119">must</em> specify an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> to a valid <a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">JSON-LD document</a> in
+ an HTTP Link Header [<cite><a href="#bib-RFC5988" class="bibref">RFC5988</a></cite>] using the <code>http://www.w3.org/ns/json-ld#context</code>
+ link relation. The referenced document <em title="must" class="rfc2119">must</em> have a top-level <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a>.
+ The <code>@context</code> subtree within that object is added to the top-level
+ <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a> of the referencing document. If an <a href="#dfn-array" title="array" class="tref internalDFN">array</a>
+ is at the top-level of the referencing document and its items are
+ <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON objects</a>, the <code>@context</code>
+ subtree is added to all <a href="#dfn-array" title="array" class="tref internalDFN">array</a> items. All extra information located outside
+ of the <code>@context</code> subtree in the referenced document <em title="must" class="rfc2119">must</em> be
+ discarded. Effectively this means that the <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a> is
+ initialized with the referenced external <a href="#dfn-context" title="context" class="tref internalDFN">context</a>.</p>
+
+ <p>The following example demonstrates the use of an external context with an
+ ordinary JSON document:</p>
+
+ <div class="example"><div class="example-title"><span>Example 26</span>: Referencing a JSON-LD context from a JSON document via an HTTP Link Header</div><pre class="example">GET /ordinary-json-document.json HTTP/1.1
+Host: example.com
+Accept: application/ld+json,application/json,*/*;q=0.1
+
+====================================
+
+HTTP/1.0 200 OK
+...
+Content-Type: <span class="diff">application/json</span>
+<span class="diff">Link: <http://json-ld.org/contexts/person.jsonld>; rel="http://www.w3.org/ns/json-ld#context"; type="application/ld+json"</span>
+
+{
+ "name": "Markus Lanthaler",
+ "homepage": "http://www.markus-lanthaler.com/",
+ "image": "http://twitter.com/account/profile_image/markuslanthaler"
+}</pre></div>
+
+ <p>Please note that <a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">JSON-LD documents</a>
+ served with the <code>application/ld+json</code>
+ media type <em title="must" class="rfc2119">must</em> have all context information, including references to external
+ contexts, within the body of the document. Contexts linked via a
+ <code>http://www.w3.org/ns/json-ld#context</code> HTTP Link Header <em title="must" class="rfc2119">must</em> be
+ ignored for such documents.</p>
+</section>
+
+<section id="string-internationalization">
+ <h3><span class="secno">6.6 </span>String Internationalization</h3>
+
+ <p>At times, it is important to annotate a <a href="#dfn-string" title="string" class="tref internalDFN">string</a>
+ with its language. In JSON-LD this is possible in a variety of ways.
+ First, it is possible to define a default language for a JSON-LD document
+ by setting the <code>@language</code> key in the <a href="#dfn-context" title="context" class="tref internalDFN">context</a>:</p>
+
+ <div class="example"><div class="example-title"><span>Example 27</span>: Setting the default language of a JSON-LD document</div><pre class="example">{
+ <span class="diff">"@context":
+ {
+ ...
+ "@language": "ja"
+ }</span>,
+ "name": <span class="diff">"花澄"</span>,
+ "occupation": <span class="diff">"科学者"</span>
+}</pre></div>
+
+ <p>The example above would associate the <code>ja</code> language
+ code with the two <a href="#dfn-string" title="string" class="tref internalDFN">strings</a> <em>花澄</em> and <em>科学者</em>.
+ Languages codes are defined in [<cite><a href="#bib-BCP47" class="bibref">BCP47</a></cite>].</p>
+
+ <p>To clear the default language for a subtree, <code>@language</code> can
+ be set to <code>null</code> in a <a href="#dfn-local-context" title="local-context" class="tref internalDFN">local context</a> as follows:</p>
+
+ <div class="example"><div class="example-title"><span>Example 28</span>: Clearing default language</div><pre class="example">{
+ "@context": {
+ ...
+ "@language": "ja"
+ },
+ "name": "花澄",
+ "details": {
+<span class="diff"> "@context": {
+ "@language": null
+ }</span>,
+ "occupation": "Ninja"
+ }
+}</pre></div>
+
+ <p>Second, it is possible to associate a language with a specific <a href="#dfn-term" title="term" class="tref internalDFN">term</a>
+ using an <a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">expanded term definition</a>:</p>
+
+ <div class="example"><div class="example-title"><span>Example 29</span>: Expanded term definition with language</div><pre class="example">{
+ "@context": {
+ ...
+ "ex": "http://example.com/vocab/",
+ "@language": "ja",
+ "name": { "@id": "ex:name", <span class="diff">"@language": null</span> },
+ "occupation": { "@id": "ex:occupation" },
+ "occupation_en": { "@id": "ex:occupation", <span class="diff">"@language": "en"</span> },
+ "occupation_cs": { "@id": "ex:occupation", <span class="diff">"@language": "cs"</span> }
+ },
+ <span class="diff">"name": "Yagyū Muneyoshi",
+ "occupation": "忍者",
+ "occupation_en": "Ninja",
+ "occupation_cs": "Nindža",</span>
+ ...
+}</pre></div>
+
+ <p>The example above would associate <em>忍者</em> with the specified default
+ language code <code>ja</code>, <em>Ninja</em> with the language code
+ <code>en</code>, and <em>Nindža</em> with the language code <code>cs</code>.
+ The value of <code>name</code>, <em>Yagyū Muneyoshi</em> wouldn't be
+ associated with any language code since <code>@language</code> was reset to
+ <a href="#dfn-null" title="null" class="tref internalDFN">null</a> in the <a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">expanded term definition</a>.</p>
+
+ <div class="note"><div class="note-title"><span>Note</span></div><p class="">Language associations can only be applied to plain
+ literal <a href="#dfn-string" title="string" class="tref internalDFN">strings</a>.
+ <a href="#dfn-typed-value" title="typed-value" class="tref internalDFN">Typed values</a> or values that are subject
+ to <a class="sec-ref" href="#type-coercion"><span class="secno">6.3</span> <span class="sec-title">Type Coercion</span></a> cannot be language tagged.</p></div>
+
+ <p>Just as in the example above, systems often need to express the value of a
+ property in multiple languages. Typically, such systems also try to ensure that
+ developers have a programmatically easy way to navigate the data structures for
+ the language-specific data. In this case, <a href="#dfn-language-map" title="language-map" class="tref internalDFN">language maps</a>
+ may be utilized.</p>
+
+ <div class="example"><div class="example-title"><span>Example 30</span>: Language map expressing a property in three languages</div><pre class="example">{
+ "@context":
+ {
+ ...
+ "occupation": { "@id": "ex:occupation", <span class="diff">"@container": "@language"</span> }
+ },
+ "name": "Yagyū Muneyoshi",
+ "occupation":
+ <span class="diff">{
+ "ja": "忍者",
+ "en": "Ninja",
+ "cs": "Nindža"
+ }</span>
+ ...
+}</pre></div>
+
+ <p>The example above expresses exactly the same information as the previous
+ example but consolidates all values in a single property. To access the
+ value in a specific language in a programming language supporting dot-notation
+ accessors for object properties, a developer may use the
+ <code>property.language</code> pattern. For example, to access the occupation
+ in English, a developer would use the following code snippet:
+ <code>obj.occupation.en</code>.</p>
+
+ <p>Third, it is possible to override the default language by using an
+ <a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">expanded value</a>:</p>
+
+ <div class="example"><div class="example-title"><span>Example 31</span>: Overriding default language using an expanded value</div><pre class="example">{
+ "@context": {
+ ...
+ "@language": "ja"
+ },
+ "name": "花澄",
+ "occupation": <span class="diff">{
+ "@value": "Scientist",
+ "@language": "en"
+ }</span>
+}</pre></div>
+
+ <p>This makes it possible to specify a plain string by omitting the
+ <code>@language</code> tag or setting it to <code>null</code> when expressing
+ it using an <a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">expanded value</a>:</p>
+
+ <div class="example"><div class="example-title"><span>Example 32</span>: Removing language information using an expanded value</div><pre class="example">{
+ "@context": {
+ ...
+ "@language": "ja"
+ },
+ "name": <span class="diff">{
+ "@value": "Frank"
+ }</span>,
+ "occupation": {
+ "@value": "Ninja",
+ "@language": "en"
+ },
+ "speciality": "手裏剣"
+}</pre></div>
+
+</section>
+
+<section id="overriding-vocab">
+<h3><span class="secno">6.7 </span>Overriding @vocab</h3>
+ <p>If <code>@vocab</code> is used but certain keys in an
+ <a href="#dfn-json-object" title="json-object" class="tref internalDFN">object</a> should not be expanded using
+ the vocabulary <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>, a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> can be explicitly set
+ to <a href="#dfn-null" title="null" class="tref internalDFN">null</a> in the <a href="#dfn-context" title="context" class="tref internalDFN">context</a>. For instance, in the
+ example below the <code>databaseId</code> member would be ignored by a
+ JSON-LD processor.</p><p></p>
+
+ <div class="example"><div class="example-title"><span>Example 33</span>: Using the null keyword to ignore data</div><pre class="example">{
+ "@context":
+ {
+ "@vocab": "http://schema.org/",
+ <span class="diff">"databaseId": null</span>
+ },
+ "name": "Gregg Kellogg",
+ <span class="diff">"databaseId": "23987520"</span>
+}</pre></div>
+</section>
+
+<section id="property-generators">
+<h3><span class="secno">6.8 </span>Property Generators</h3>
+
+<p>At times, an author may find that they need to express the same value for
+multiple properties. The simplest approach to accomplish this goal would be
+to do the following:</p>
+
+<div class="example"><div class="example-title"><span>Example 34</span>: Verbose expression of multiple properties with the same value</div><pre class="example">{
+ "@context":
+ {
+ <span class="diff">"title1": "http://purl.org/dc/terms/title"</span>,
+ <span class="diff">"title2": "http://schema.org/name"</span>,
+ <span class="diff">"title3": "http://www.w3.org/2000/01/rdf-schema#label"</span>
+ },
+ "@id": "http://example.com/book",
+ <span class="diff">"title1": "The Count of Monte Cristo"</span>,
+ <span class="diff">"title2": "The Count of Monte Cristo"</span>,
+ <span class="diff">"title3": "The Count of Monte Cristo"</span>
+}</pre></div>
+
+<p>Unfortunately, the approach above produces redundant data and would become a
+publishing burden for large data sets.
+In these situations, the author may use
+a <dfn id="dfn-property-generator" title="property-generator">property generator</dfn> to express a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> that maps to
+multiple <a href="#dfn-property" title="property" class="tref internalDFN">properties</a> in the <a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">JSON-LD graph</a>.
+This method can be accomplished by using the following markup pattern:</p>
+
+<div class="example"><div class="example-title"><span>Example 35</span>: Generating multiple properties using a single term</div><pre class="example">{
+ "@context":
+ {
+ <span class="diff">"title": { "@id": [ "http://purl.org/dc/terms/title",
+ "http://schema.org/name",
+ "http://www.w3.org/2000/01/rdf-schema#label" ] }</span>
+ },
+ "@id": "http://example.com/book",
+ <span class="diff">"title": "The Count of Monte Cristo"</span>
+}</pre></div>
+
+<p>While the term above is only used once outside of the <code>@context</code>,
+the document above will be interpreted like so:</p>
+
+<table class="example">
+<thead>
+ <tr><th>Subject</th>
+ <th>Property</th>
+ <th>Value</th>
+</tr></thead>
+<tbody>
+<tr>
+ <td>http://example.com/book</td>
+ <td>http://purl.org/dc/terms/title</td>
+ <td>The Count of Monte Cristo</td>
+</tr>
+<tr>
+ <td>http://example.com/book</td>
+ <td>http://schema.org/name</td>
+ <td>The Count of Monte Cristo</td>
+</tr>
+<tr>
+ <td>http://example.com/book</td>
+ <td>http://www.w3.org/2000/01/rdf-schema#label</td>
+ <td>The Count of Monte Cristo</td>
+</tr>
+</tbody>
+</table>
+
+</section>
+
+<section id="iri-expansion-within-a-context">
+ <h3><span class="secno">6.9 </span><abbr title="Internationalized Resource Identifier">IRI</abbr> Expansion Within a Context</h3>
+ <p>In general, normal <abbr title="Internationalized Resource Identifier">IRI</abbr> expansion rules apply
+ anywhere an <abbr title="Internationalized Resource Identifier">IRI</abbr> is expected (see <a class="sec-ref" href="#iris"><span class="secno">5.2</span> <span class="sec-title">IRIs</span></a>). Within
+ a <a href="#dfn-context" title="context" class="tref internalDFN">context</a> definition, this can mean that terms defined
+ within the context may also be used within that context as long as
+ there are no circular dependencies. For example, it is common to use
+ the <code>xsd</code> namespace when defining <a href="#dfn-typed-value" title="typed-value" class="tref internalDFN">typed value</a>s:</p>
+<div class="example"><div class="example-title"><span>Example 36</span>: IRI expansion within a context</div><pre class="example">{
+ "@context":
+ {
+ <span class="diff">"xsd": "http://www.w3.org/2001/XMLSchema#"</span>,
+ "name": "http://xmlns.com/foaf/0.1/name",
+ "age":
+ {
+ "@id": "http://xmlns.com/foaf/0.1/age",
+ "@type": <span class="diff">"xsd:integer"</span>
+ },
+ "homepage":
+ {
+ "@id": "http://xmlns.com/foaf/0.1/homepage",
+ "@type": "@id"
+ }
+ },
+ ...
+}</pre></div>
+<p>In this example, the <code>xsd</code> <a href="#dfn-term" title="term" class="tref internalDFN">term</a> is defined
+ and used as a <a href="#dfn-prefix" title="prefix" class="tref internalDFN">prefix</a> for the <code>@type</code> coercion
+ of the <code>age</code> property.</p>
+
+<p><a href="#dfn-term" title="term" class="tref internalDFN">Terms</a> may also be used when defining the <abbr title="Internationalized Resource Identifier">IRI</abbr> of another
+<a href="#dfn-term" title="term" class="tref internalDFN">term</a>:</p>
+
+<div class="example"><div class="example-title"><span>Example 37</span>: Using a term to define the IRI of another term within a context</div><pre class="example">{
+ "@context":
+ {
+ <span class="diff">"foaf": "http://xmlns.com/foaf/0.1/"</span>,
+ "xsd": "http://www.w3.org/2001/XMLSchema#",
+ "name": <span class="diff">"foaf:name"</span>,
+ "age":
+ {
+ "@id": <span class="diff">"foaf:age"</span>,
+ "@type": "xsd:integer"
+ },
+ "homepage":
+ {
+ "@id": <span class="diff">"foaf:homepage"</span>,
+ "@type": "@id"
+ }
+ },
+ ...
+}</pre></div>
+
+<p><a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">Compact IRIs</a>
+ and <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a> may be used on the left-hand side of a
+ <a href="#dfn-term" title="term" class="tref internalDFN">term</a> definition.</p>
+
+<div class="example"><div class="example-title"><span>Example 38</span>: Using a compact IRI as a term</div><pre class="example">{
+ "@context":
+ {
+ <span class="diff">"foaf": "http://xmlns.com/foaf/0.1/"</span>,
+ "xsd": "http://www.w3.org/2001/XMLSchema#",
+ "name": "foaf:name",
+ "<span class="diff">foaf:age</span>":
+ {
+ "@type": "xsd:integer"
+ },
+ "<span class="diff">foaf:homepage</span>":
+ <span class="diff">{
+ "@type": "@id"
+ }</span>
+ },
+ ...
+}</pre></div>
+
+<p>
+In this example, the <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact <abbr title="Internationalized Resource Identifier">IRI</abbr></a> form is used in two different
+ways.
+In the first approach, <code>foaf:age</code> declares both the
+<a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> for the <a href="#dfn-term" title="term" class="tref internalDFN">term</a> (using short-form) as well as the
+<code>@type</code> associated with the <a href="#dfn-term" title="term" class="tref internalDFN">term</a>. In the second
+approach, only the <code>@type</code> associated with the <a href="#dfn-term" title="term" class="tref internalDFN">term</a> is
+specified. The full <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> for
+<code>foaf:homepage</code> is determined by looking up the <code>foaf</code>
+<a href="#dfn-prefix" title="prefix" class="tref internalDFN">prefix</a> in the
+<a href="#dfn-context" title="context" class="tref internalDFN">context</a>.
+</p>
+
+<p>
+<a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">Absolute IRIs</a> may also be used in the key position in a <a href="#dfn-context" title="context" class="tref internalDFN">context</a>:
+</p>
+
+<div class="example"><div class="example-title"><span>Example 39</span>: Associating context definitions with absolute IRIs</div><pre class="example">{
+ "@context":
+ {
+ "foaf": "http://xmlns.com/foaf/0.1/",
+ "xsd": "http://www.w3.org/2001/XMLSchema#",
+ "name": "foaf:name",
+ "foaf:age":
+ {
+ "@id": "foaf:age",
+ "@type": "xsd:integer"
+ },
+ "<span class="diff">http://xmlns.com/foaf/0.1/homepage</span>":
+ {
+ "@type": "@id"
+ }
+ },
+ ...
+}</pre></div>
+
+<p>In order for the <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a> to match above, the <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a>
+ needs to be used in the <a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">JSON-LD document</a>. Also note that <code>foaf:homepage</code>
+ will not use the <code>{ "@type": "@id" }</code> declaration because
+ <code>foaf:homepage</code> is not the same as <code>http://xmlns.com/foaf/0.1/homepage</code>.
+ That is, <a href="#dfn-term" title="term" class="tref internalDFN">terms</a> are looked up in a <a href="#dfn-context" title="context" class="tref internalDFN">context</a> using
+ direct string comparison before the <a href="#dfn-prefix" title="prefix" class="tref internalDFN">prefix</a> lookup mechanism is applied.</p>
+
+<div class="note"><div class="note-title"><span>Note</span></div><p class="">While it is possible to define a <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact <abbr title="Internationalized Resource Identifier">IRI</abbr></a>, or
+ an <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a> to expand to some other unrelated <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>
+ (for example, <code>foaf:name</code> expanding to
+ <code>http://example.org/unrelated#species</code>), such usage is strongly
+ discouraged.</p></div>
+
+<p>The only exception for using terms in the <a href="#dfn-context" title="context" class="tref internalDFN">context</a> is that
+ circular definitions are not allowed. That is,
+ a definition of <em>term1</em> cannot depend on the
+ definition of <em>term2</em> if <em>term2</em> also depends on
+ <em>term1</em>. For example, the following <a href="#dfn-context" title="context" class="tref internalDFN">context</a> definition
+ is illegal:</p>
+<div class="example"><div class="example-title"><span>Example 40</span>: Illegal circular definition of terms within a context</div><pre class="example">{
+ "@context":
+ {
+ <span class="diff">"term1": "term2:foo",
+ "term2": "term1:bar"</span>
+ },
+ ...
+}</pre></div>
+</section>
+
+<section id="sets-and-lists">
+<h3><span class="secno">6.10 </span>Sets and Lists</h3>
+
+<p>A JSON-LD author can express multiple values in a compact way by using
+ <a href="#dfn-array" title="array" class="tref internalDFN">arrays</a>. Since graphs do not describe ordering for links
+ between nodes, arrays in JSON-LD do not provide an ordering of the
+ contained elements by default. This is exactly the opposite from regular JSON
+ arrays, which are ordered by default. For example, consider the following
+ simple document:</p>
+
+<div class="example"><div class="example-title"><span>Example 41</span>: Multiple values with no inherent order</div><pre class="example">{
+...
+ "@id": "http://example.org/people#joebob",
+ "nick": <span class="diff">[ "joe", "bob", "JB" ]</span>,
+...
+}</pre></div>
+
+<p>The markup shown above would result in the following data being generated,
+ each relating the node to an individual value, with no inherent order:</p>
+
+<table class="example">
+<thead>
+ <tr><th>Subject</th>
+ <th>Property</th>
+ <th>Value</th>
+</tr></thead>
+<tbody>
+<tr>
+ <td>http://example.org/people#joebob</td>
+ <td>http://xmlns.com/foaf/0.1/nick</td>
+ <td>joe</td>
+</tr>
+<tr>
+ <td>http://example.org/people#joebob</td>
+ <td>http://xmlns.com/foaf/0.1/nick</td>
+ <td>bob</td>
+</tr>
+<tr>
+ <td>http://example.org/people#joebob</td>
+ <td>http://xmlns.com/foaf/0.1/nick</td>
+ <td>JB</td>
+</tr>
+</tbody>
+</table>
+
+<p>Multiple values may also be expressed using the expanded form:</p>
+
+<div class="example"><div class="example-title"><span>Example 42</span>: Using an expanded form to set multiple values</div><pre class="example">{
+ "@id": "http://example.org/articles/8",
+ "dc:title": <span class="diff">
+ [
+ {
+ "@value": "Das Kapital",
+ "@language": "de"
+ },
+ {
+ "@value": "Capital",
+ "@language": "en"
+ }
+ ]</span>
+}</pre></div>
+
+<p>The markup shown above would generate the following data, again with
+ no inherent order:</p>
+
+<table class="example">
+<thead>
+ <tr><th>Subject</th>
+ <th>Property</th>
+ <th>Value</th>
+ <th>Language</th>
+</tr></thead>
+<tbody>
+<tr>
+ <td>http://example.org/articles/8</td>
+ <td>http://purl.org/dc/terms/title</td>
+ <td>Das Kapital</td>
+ <td>de</td>
+</tr>
+<tr>
+ <td>http://example.org/articles/8</td>
+ <td>http://purl.org/dc/terms/title</td>
+ <td>Capital</td>
+ <td>en</td>
+</tr>
+</tbody>
+</table>
+
+<p>As the notion of ordered collections is rather important in data
+ modeling, it is useful to have specific language support. In JSON-LD,
+ a list may be represented using the <code>@list</code> <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a> as follows:</p>
+<div class="example"><div class="example-title"><span>Example 43</span>: An ordered collection of values in JSON-LD</div><pre class="example">{
+...
+ "@id": "http://example.org/people#joebob",
+ "foaf:nick":
+ <span class="diff">{
+ "@list": [ "joe", "bob", "jaybee" ]
+ }</span>,
+...
+}</pre></div>
+
+<p>This describes the use of this <a href="#dfn-array" title="array" class="tref internalDFN">array</a> as being ordered,
+ and order is maintained when processing a document. If every use of a given multi-valued
+ property is a list, this may be abbreviated by setting <code>@container</code>
+ to <code>@list</code> in the <a href="#dfn-context" title="context" class="tref internalDFN">context</a>:</p>
+<div class="example"><div class="example-title"><span>Example 44</span>: Specifying that a collection is ordered in the context</div><pre class="example">{
+ <span class="diff">"@context":
+ {
+ ...
+ "nick":
+ {
+ "@id": "http://xmlns.com/foaf/0.1/nick",
+ "@container": "@list"
+ }
+ }</span>,
+...
+ "@id": "http://example.org/people#joebob",
+ "nick": <span class="diff">[ "joe", "bob", "jaybee" ]</span>,
+...
+}</pre></div>
+
+<div class="note"><div class="note-title"><span>Note</span></div><p class="">List of lists are not allowed in this version of JSON-LD.
+ This decision was made due to the extreme amount of added complexity when
+ processing lists of lists.</p></div>
+
+<p>While <code>@list</code> is used to describe <em>ordered lists</em>,
+ the <code>@set</code> keyword is used to describe <em>unordered sets</em>.
+ The use of <code>@set</code> in the body of a JSON-LD document
+ is optimized away when processing the document, as it is just syntactic
+ sugar. However, <code>@set</code> is helpful when used within the context
+ of a document.
+ Values of terms associated with a <code>@set</code> or <code>@list</code> container
+ are always represented in the form of an <a href="#dfn-array" title="array" class="tref internalDFN">array</a>,
+ even if there is just a single value that would otherwise be optimized to
+ a non-array form in compact form (see
+ <a class="sec-ref" href="#compact-document-form"><span class="secno">6.16</span> <span class="sec-title">Compact Document Form</span></a>). This makes post-processing of
+ JSON-LD documents easier as the data is always in array form, even if the
+ array only contains a single value.</p>
+
+<div class="note"><div class="note-title"><span>Note</span></div><p class="">The use of <code>@container</code> in the body of a JSON-LD
+ document has no meaning and is not allowed by the JSON-LD grammar
+ (see <a class="sec-ref" href="#json-ld-grammar"><span class="secno">B.</span> <span class="sec-title">JSON-LD Grammar</span></a>).</p></div>
+
+</section>
+
+<section id="embedding">
+ <h3><span class="secno">6.11 </span>Embedding</h3>
+
+ <p><dfn id="dfn-embedding" title="embedding">Embedding</dfn> is a JSON-LD feature that allows an author to
+ use <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node objects</a> as
+ <a href="#dfn-property" title="property" class="tref internalDFN">property</a> values. This is a commonly used mechanism for
+ creating a parent-child relationship between two <a href="#dfn-node" title="node" class="tref internalDFN">nodes</a>.</p>
+
+ <p>The example shows two nodes related by a property from the first node:</p>
+
+ <div class="example"><div class="example-title"><span>Example 45</span>: Embedding a node object as property value of another node object</div><pre class="example">{
+...
+ "name": "Manu Sporny",
+ "<span class="diff">knows</span>":
+ {
+ "<span class="diff">@type</span>": "<span class="diff">Person</span>",
+ "<span class="diff">name</span>": "<span class="diff">Gregg Kellogg</span>",
+ }
+...
+}</pre></div>
+
+ <p>
+ A <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a>, like the one used above, may be used in
+ any value position in the body of a JSON-LD document.</p>
+</section>
+
+<section id="named-graphs">
+ <h3><span class="secno">6.12 </span>Named Graphs</h3>
+
+ <p>At times, it is necessary to make statements about a <a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">JSON-LD graph</a>
+ itself, rather than just a single <a href="#dfn-node" title="node" class="tref internalDFN">node</a>. This can be done by
+ grouping a set of <a href="#dfn-node" title="node" class="tref internalDFN">nodes</a> using the <code>@graph</code>
+ <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a>. A developer may also name data expressed using the
+ <code>@graph</code> <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a> by pairing it with an
+ <code>@id</code> <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a> as shown in the following example:</p>
+
+ <div class="example"><div class="example-title"><span>Example 46</span>: Identifying and making statements about a graph</div><pre class="example">{
+ "@context": {
+ "generatedAt": "http://www.w3.org/ns/prov#generatedAtTime",
+ "Person": "http://xmlns.com/foaf/0.1/Person",
+ "name": "http://xmlns.com/foaf/0.1/name",
+ "knows": "http://xmlns.com/foaf/0.1/knows",
+ "xsd": "http://www.w3.org/2001/XMLSchema#"
+ },
+ <span class="diff">"@id": "http://example.org/graphs/73",
+ "generatedAt": { "@value": "2012-04-09", "@type": "xsd:date" },
+ "@graph":</span>
+ [
+ {
+ "@id": "http://manu.sporny.org/i/public",
+ "@type": "Person",
+ "name": "Manu Sporny",
+ "knows": "http://greggkellogg.net/foaf#me"
+ },
+ {
+ "@id": "http://greggkellogg.net/foaf#me",
+ "@type": "Person",
+ "name": "Gregg Kellogg",
+ "knows": "http://manu.sporny.org/i/public"
+ }
+ ]
+}</pre></div>
+
+ <p>The example above expresses a <em>named</em> <a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">JSON-LD graph</a>
+ that is identified by the <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>
+ <code>http://example.org/graphs/73</code>. That graph is composed of the
+ statements about Manu and Gregg. Metadata about the graph itself is also
+ expressed via the <code>generatedAt</code> property, which specifies when
+ the graph was generated. An alternative view of the
+ information above is represented in table form below:</p>
+
+ <table class="example">
+ <thead>
+ <tr><th>Graph</th>
+ <th>Subject</th>
+ <th>Property</th>
+ <th>Value</th>
+ <th>Value Type</th>
+ </tr></thead>
+ <tbody>
+ <tr>
+ <td>http://example.org/graphs/73</td>
+ <td>http://example.org/graphs/73</td>
+ <td>http://www.w3.org/ns/prov#generatedAtTime</td>
+ <td>2012-04-09</td>
+ <td>http://www.w3.org/2001/XMLSchema#date</td>
+ </tr>
+ <tr>
+ <td>http://example.org/graphs/73</td>
+ <td>http://manu.sporny.org/i/public</td>
+ <td>http://www.w3.org/2001/XMLSchema#type</td>
+ <td>http://xmlns.com/foaf/0.1/Person</td>
+ <td></td>
+ </tr>
+ <tr>
+ <td>http://example.org/graphs/73</td>
+ <td>http://manu.sporny.org/i/public</td>
+ <td>http://xmlns.com/foaf/0.1/name</td>
+ <td>Manu Sporny</td>
+ <td></td>
+ </tr>
+ <tr>
+ <td>http://example.org/graphs/73</td>
+ <td>http://manu.sporny.org/i/public</td>
+ <td>http://xmlns.com/foaf/0.1/knows</td>
+ <td>http://greggkellogg.net/foaf#me</td>
+ <td></td>
+ </tr>
+ <tr>
+ <td>http://example.org/graphs/73</td>
+ <td>http://greggkellogg.net/foaf#me</td>
+ <td>http://www.w3.org/2001/XMLSchema#type</td>
+ <td>http://xmlns.com/foaf/0.1/Person</td>
+ <td></td>
+ </tr>
+ <tr>
+ <td>http://example.org/graphs/73</td>
+ <td>http://greggkellogg.net/foaf#me</td>
+ <td>http://xmlns.com/foaf/0.1/name</td>
+ <td>Gregg Kellogg</td>
+ <td></td>
+ </tr>
+ <tr>
+ <td>http://example.org/graphs/73</td>
+ <td>http://greggkellogg.net/foaf#me</td>
+ <td>http://xmlns.com/foaf/0.1/knows</td>
+ <td>http://manu.sporny.org/i/public</td>
+ <td></td>
+ </tr>
+ </tbody>
+ </table>
+
+ <p>When a JSON-LD document's top-level structure is an
+ <a href="#dfn-json-object" title="json-object" class="tref internalDFN">object</a> that contains no other
+ <a href="#dfn-property" title="property" class="tref internalDFN">properties</a> than <code>@graph</code> and
+ optionally <code>@context</code> (properties that are not mapped to an
+ <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> or a <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a> are ignored),
+ <code>@graph</code> is considered to express the otherwise implicit
+ <a href="#dfn-default-graph" title="default-graph" class="tref internalDFN">default graph</a>. This mechanism can be useful when a number
+ of <a href="#dfn-node" title="node" class="tref internalDFN">nodes</a> exist at the document's top level that
+ share the same <a href="#dfn-context" title="context" class="tref internalDFN">context</a>. The <code>@graph</code> keyword
+ collects such nodes in an <a href="#dfn-array" title="array" class="tref internalDFN">array</a> and allows the use of a
+ shared context.</p>
+
+ <div class="example"><div class="example-title"><span>Example 47</span>: Using @graph to explicitly express the default graph</div><pre class="example">{
+ "@context": ...,
+ "<span class="diff">@graph</span>":
+ [
+ {
+ "@id": "http://manu.sporny.org/i/public",
+ "@type": "foaf:Person",
+ "name": "Manu Sporny",
+ "knows": "http://greggkellogg.net/foaf#me"
+ },
+ {
+ "@id": "http://greggkellogg.net/foaf#me",
+ "@type": "foaf:Person",
+ "name": "Gregg Kellogg",
+ "knows": "http://manu.sporny.org/i/public"
+ }
+ ]
+}</pre></div>
+
+ <p>In this case, embedding doesn't work as each <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a>
+ references the other. This is equivalent to using multiple
+ <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node objects</a> in array and defining
+ the <code>@context</code> within each <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a>:</p>
+
+ <div class="example"><div class="example-title"><span>Example 48</span>: Context needs to be duplicated if @graph is not used</div><pre class="example">[
+ {
+ <span class="diff">"@context": ...,</span>
+ "@id": "http://manu.sporny.org/i/public",
+ "@type": "foaf:Person",
+ "name": "Manu Sporny",
+ "knows": "http://greggkellogg.net/foaf#me"
+ },
+ {
+ <span class="diff">"@context": ...,</span>
+ "@id": "http://greggkellogg.net/foaf#me",
+ "@type": "foaf:Person",
+ "name": "Gregg Kellogg",
+ "knows": "http://manu.sporny.org/i/public"
+ }
+]</pre></div>
+
+</section>
+
+<section id="identifying-blank-nodes">
+ <h3><span class="secno">6.13 </span>Identifying Blank Nodes</h3>
+
+ <p>At times, it becomes necessary to be able to express information without
+ being able to uniquely identify the <a href="#dfn-node" title="node" class="tref internalDFN">node</a>.
+ This type of node is called a <a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">blank node</a>
+ (see <cite><a href="http://www.w3.org/TR/rdf11-concepts/#section-blank-nodes">Section 3.4: Blank Nodes</a></cite>
+ of [<cite><a href="#bib-RDF-CONCEPTS" class="bibref">RDF-CONCEPTS</a></cite>]). In JSON-LD, <a href="#dfn-blank-node-identifier" title="blank-node-identifier" class="tref internalDFN">blank node identifiers</a> are
+ automatically created if an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> is not specified using the <code>@id</code> <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a>.
+ However, authors may provide identifiers for <a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">blank nodes</a>
+ by using the special <code>_</code> (underscore) <a href="#dfn-prefix" title="prefix" class="tref internalDFN">prefix</a>. This allows one
+ to reference the node locally within the document, but makes it impossible to reference
+ the node from an external document. The <a href="#dfn-blank-node-identifier" title="blank-node-identifier" class="tref internalDFN">blank node identifier</a> is scoped
+ to the document in which it is used.</p>
+
+ <div class="example"><div class="example-title"><span>Example 49</span>: Specifying a local blank node identifier</div><pre class="example">{
+...
+ "@id": "<span class="diff">_:foo</span>",
+...
+}</pre></div>
+
+ <p>The example above would set the node to <code>_:foo</code>, which can
+ then be used elsewhere in the JSON-LD document to refer back to the
+ <a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">blank node</a>. If a developer finds that they refer to the <a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">blank node</a>
+ more than once, they should consider naming the node using a dereferenceable
+ <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> so that it can also be referenced from other documents.</p>
+</section>
+
+<section id="aliasing-keywords">
+ <h3><span class="secno">6.14 </span>Aliasing Keywords</h3>
+
+ <p>Each of the JSON-LD <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keywords</a>,
+ except for <code>@context</code>, may be aliased to application-specific
+ keywords. This feature allows legacy JSON content to be utilized
+ by JSON-LD by re-using JSON keys that already exist in legacy documents.
+ This feature also allows developers to design domain-specific implementations
+ using only the JSON-LD <a href="#dfn-context" title="context" class="tref internalDFN">context</a>.</p>
+
+ <div class="example"><div class="example-title"><span>Example 50</span>: Aliasing keywords</div><pre class="example">{
+ "@context":
+ {
+ <span class="diff">"url": "@id"</span>,
+ <span class="diff">"a": "@type"</span>,
+ "name": "http://xmlns.com/foaf/0.1/name"
+ },
+ "<span class="diff">url</span>": "http://example.com/about#gregg",
+ "<span class="diff">a</span>": "http://xmlns.com/foaf/0.1/Person",
+ "name": "Gregg Kellogg"
+}</pre></div>
+
+ <p>In the example above, the <code>@id</code> and <code>@type</code>
+ <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keywords</a> have been given the aliases
+ <strong>url</strong> and <strong>a</strong>, respectively.</p>
+
+ <p>Since keywords cannot be redefined, they can also not be aliased to
+ other keywords. Every statement in the context having a keyword
+ as the key (as in
+ <code style="white-space: nowrap">{ "@type": ... }</code>) will be
+ ignored when being processed.</p>
+</section>
+
+<section id="expanded-document-form">
+<h3><span class="secno">6.15 </span>Expanded Document Form</h3>
+<p>The JSON-LD Algorithms and API specification [<cite><a href="#bib-JSON-LD-API" class="bibref">JSON-LD-API</a></cite>]
+ defines a method for <em>expanding</em> a JSON-LD document.
+ Expansion is the process of taking a JSON-LD document and applying a
+ <code>@context</code> such that all IRIs, types, and values
+ are expanded so that the <code>@context</code> is no longer necessary.</p>
+
+<p>For example, assume the following JSON-LD input document:</p>
+
+<div class="example"><div class="example-title"><span>Example 51</span>: Sample JSON-LD document</div><pre class="example">{
+ "@context":
+ {
+ "name": "http://xmlns.com/foaf/0.1/name",
+ "homepage": {
+ "@id": "http://xmlns.com/foaf/0.1/homepage",
+ "@type": "@id"
+ }
+ },
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/"
+}</pre></div>
+
+<p>Running the JSON-LD Expansion algorithm against the JSON-LD input document
+ provided above would result in the following output:</p>
+
+<div class="example"><div class="example-title"><span>Example 52</span>: Expanded form for the previous example</div><pre class="example">[
+ {
+ "http://xmlns.com/foaf/0.1/name": [
+ { "@value": "Manu Sporny" }
+ ],
+ "http://xmlns.com/foaf/0.1/homepage": [
+ { "@id": "http://manu.sporny.org/" }
+ ]
+ }
+]</pre></div>
+
+<p>Expanded document form is useful when an application has to process input
+data in a deterministic form. It has been optimized to ensure that the code
+that developers have to write is minimized compared to the code that would
+have to be written to operate on
+<a class="sec-ref" href="#compact-document-form"><span class="secno">6.16</span> <span class="sec-title">Compact Document Form</span></a>.</p>
+
+</section>
+
+<section id="compact-document-form">
+<h3><span class="secno">6.16 </span>Compact Document Form</h3>
+<p>The JSON-LD Algorithms and API specification [<cite><a href="#bib-JSON-LD-API" class="bibref">JSON-LD-API</a></cite>]
+ defines a method for <em>compacting</em> a JSON-LD document.
+ Compaction is the process of taking a JSON-LD document and applying a
+ context such that a very compact form of the document is generated.
+ At times, a JSON-LD document may be received that is not in its most
+ compact form. The JSON-LD Algorithms, via an API, provides a way to compact a
+ JSON-LD document.</p>
+
+<p>For example, assume the following JSON-LD input document:</p>
+
+<div class="example"><div class="example-title"><span>Example 53</span>: Sample expanded JSON-LD document</div><pre class="example">[
+ {
+ "http://xmlns.com/foaf/0.1/name": [ "Manu Sporny" ],
+ "http://xmlns.com/foaf/0.1/homepage": [
+ {
+ "@id": "http://manu.sporny.org/"
+ }
+ ]
+ }
+]</pre></div>
+
+<p>Additionally, assume the following developer-supplied JSON-LD context:</p>
+
+<div class="example"><div class="example-title"><span>Example 54</span>: Sample context</div><pre class="example">{
+ "@context": {
+ "name": "http://xmlns.com/foaf/0.1/name",
+ "homepage": {
+ "@id": "http://xmlns.com/foaf/0.1/homepage",
+ "@type": "@id"
+ }
+ }
+}</pre></div>
+
+<p>Running the JSON-LD Compaction algorithm given the context supplied above
+ against the JSON-LD input document provided above would result in the following
+ output:</p>
+
+<div class="example"><div class="example-title"><span>Example 55</span>: Compact form of the sample document once sample context has been applied</div><pre class="example">{
+ "@context": {
+ "name": "http://xmlns.com/foaf/0.1/name",
+ "homepage": {
+ "@id": "http://xmlns.com/foaf/0.1/homepage",
+ "@type": "@id"
+ }
+ },
+ "name": "Manu Sporny",
+ "homepage": "http://manu.sporny.org/"
+}</pre></div>
+
+<p>The compaction algorithm enables a developer to map any document into an
+ application-specific compacted form. The process consists of
+ expanding the document (see <a class="sec-ref" href="#expanded-document-form"><span class="secno">6.15</span> <span class="sec-title">Expanded Document Form</span></a>) and then
+ using a developer-supplied context to compact the expanded document.
+ While the context provided above mapped <code>http://xmlns.com/foaf/0.1/name</code>
+ to <strong>name</strong>, it could have also mapped it to any arbitrary
+ <a href="#dfn-term" title="term" class="tref internalDFN">term</a> provided by the developer. This powerful mechanism allows
+ the developer to re-shape the incoming JSON data into a format that is
+ optimized for their application.</p>
+</section>
+
+<section id="data-indexing">
+ <h3><span class="secno">6.17 </span>Data Indexing</h3>
+
+ <p>Databases are typically used to make access to
+ data more efficient. Developers often extend this sort of functionality into
+ their application data to deliver similar performance gains. Often this
+ data does not have any meaning from a Linked Data standpoint, but is
+ still useful for an application.</p>
+
+ <p>JSON-LD introduces the notion of <a href="#dfn-index-map" title="index-map" class="tref internalDFN">index maps</a>
+ that can be used to structure data into a form that is
+ more efficient to access. The data indexing feature allows an author to
+ structure data using a simpley key-value map where the keys do not map
+ to <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a>. This enables direct access to data
+ instead of having to scan an array in search of a specific item.
+ In JSON-LD such data can be specified by associating the
+ <code>@index</code> <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a> with a
+ <code>@container</code> declaration in the context:</p>
+
+ <div class="example"><div class="example-title"><span>Example 56</span>: Indexing data in JSON-LD</div><pre class="example">{
+ "@context":
+ {
+ "schema": "http://schema.org/",
+ "name": "schema:name",
+ "body": "schema:articleBody",
+ "words": "schema:wordCount",
+ "post": {
+ "@id": "schema:blogPost",
+ <span class="diff">"@container": "@index"</span>
+ }
+ },
+ "@id": "http://example.com/",
+ "@type": "schema:Blog",
+ "name": "World Financial News",
+ <span class="diff">"post": {
+ "en": {
+ "@id": "http://example.com/posts/1/en",
+ "body": "World commodities were up today with heavy trading of crude oil...",
+ "words": 1539
+ },
+ "de": {
+ "@id": "http://example.com/posts/1/de",
+ "body": "Die Werte an Warenbörsen stiegen im Sog eines starken Handels von Rohöl...",
+ "words": 1204
+ }</span>
+ }
+}</pre></div>
+
+ <p>In the example above, the <strong>blogPost</strong> <a href="#dfn-term" title="term" class="tref internalDFN">term</a> has
+ been marked as an <a href="#dfn-index-map" title="index-map" class="tref internalDFN">index map</a>. The <strong>en</strong>,
+ <strong>de</strong>, and <strong>ja</strong> keys will be ignored
+ semantically, but preserved syntactically, by the JSON-LD Processor.
+ This allows a developer to access the German version
+ of the <strong>blogPost</strong> using the following code snippet:
+ <code>obj.blogPost.de</code>.</p>
+
+ <p>The interpretation of the data above is expressed in
+ the table below. Note how the index keys do not appear in the Linked Data
+ below, but would continue to exist if the document were compacted or
+ expanded (see <a class="sec-ref" href="#compact-document-form"><span class="secno">6.16</span> <span class="sec-title">Compact Document Form</span></a> and
+ <a class="sec-ref" href="#expanded-document-form"><span class="secno">6.15</span> <span class="sec-title">Expanded Document Form</span></a>) using a JSON-LD processor:</p>
+
+ <table class="example">
+ <thead>
+ <tr><th>Subject</th>
+ <th>Property</th>
+ <th>Value</th>
+ </tr></thead>
+ <tbody>
+ <tr>
+ <td>http://example.com/</td>
+ <td>http://www.w3.org/1999/02/22-rdf-syntax-ns#type</td>
+ <td>http://schema.org/Blog</td>
+ </tr>
+ <tr>
+ <td>http://example.com/</td>
+ <td>http://schema.org/name</td>
+ <td>World Financial News</td>
+ </tr>
+ <tr>
+ <td>http://example.com/</td>
+ <td>http://schema.org/blogPost</td>
+ <td>http://example.com/posts/1/en</td>
+ </tr>
+ <tr>
+ <td>http://example.com/</td>
+ <td>http://schema.org/blogPost</td>
+ <td>http://example.com/posts/1/de</td>
+ </tr>
+ <tr>
+ <td>http://example.com/posts/1/en</td>
+ <td>http://schema.org/articleBody</td>
+ <td>World commodities were up today with heavy trading of crude oil...</td>
+ </tr>
+ <tr>
+ <td>http://example.com/posts/1/en</td>
+ <td>http://schema.org/wordCount</td>
+ <td>1539</td>
+ </tr>
+ <tr>
+ <td>http://example.com/posts/1/de</td>
+ <td>http://schema.org/articleBody</td>
+ <td>Die Werte an Warenbörsen stiegen im Sog eines starken Handels von Rohöl...</td>
+ </tr>
+ <tr>
+ <td>http://example.com/posts/1/de</td>
+ <td>http://schema.org/wordCount</td>
+ <td>1204</td>
+ </tr>
+ </tbody>
+ </table>
+</section>
+
+</section>
+
+<section id="data-model" class="appendix normative">
+ <!--OddPage--><h2><span class="secno">A. </span>Data Model</h2>
+
+ <p>JSON-LD is a serialization format for <a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">Linked Data</a> based on JSON.
+ It is therefore important to distinguish between the syntax, which is defined
+ by JSON in [<cite><a href="#bib-RFC4627" class="bibref">RFC4627</a></cite>], and <dfn id="dfn-json-ld-data-model" title="json-ld-data-model">JSON-LD's data model</dfn>
+ which is defined as follows:</p>
+
+ <ul>
+ <li>A <dfn id="dfn-json-ld-document" title="json-ld-document">JSON-LD document</dfn> serializes a collection of
+ <a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">JSON-LD graphs</a> and comprises exactly one
+ <dfn id="dfn-default-graph" title="default-graph">default graph</dfn> and zero or more <dfn id="dfn-named-graph" title="named-graph">named graphs</dfn>.</li>
+ <li>The <a href="#dfn-default-graph" title="default-graph" class="tref internalDFN">default graph</a> does not have a name and <em title="may" class="rfc2119">may</em> be empty.</li>
+ <li>Each <a href="#dfn-named-graph" title="named-graph" class="tref internalDFN">named graph</a> is a pair consisting of an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> or
+ <a href="#dfn-blank-node-identifier" title="blank-node-identifier" class="tref internalDFN">blank node identifier</a> (the <dfn id="dfn-graph-name" title="graph-name">graph name</dfn>) and a <a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">JSON-LD graph</a>.
+ Whenever possible, the <a href="#dfn-graph-name" title="graph-name" class="tref internalDFN">graph name</a> <em title="should" class="rfc2119">should</em> be an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>.</li>
+ <li>A <dfn id="dfn-json-ld-graph" title="json-ld-graph">JSON-LD graph</dfn> is a labeled directed graph, i.e., a set of
+ <a href="#dfn-node" title="node" class="tref internalDFN">nodes</a> connected by <a href="#dfn-edge" title="edge" class="tref internalDFN">edges</a>.</li>
+ <li>Every <dfn id="dfn-edge" title="edge">edge</dfn> has a direction associated with it and is labeled with
+ an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> or a <a href="#dfn-blank-node-identifier" title="blank-node-identifier" class="tref internalDFN">blank node identifier</a>. Within the JSON-LD syntax
+ these edge labels are called <dfn id="dfn-property" title="property">properties</dfn>. Whenever possible, an
+ <a href="#dfn-edge" title="edge" class="tref internalDFN">edge</a> <em title="should" class="rfc2119">should</em> be labeled with an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>.</li>
+ <li>Every <dfn id="dfn-node" title="node">node</dfn> is an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>, a <a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">blank node</a>,
+ a <a href="#dfn-json-ld-value" title="json-ld-value" class="tref internalDFN">JSON-LD value</a>, or a <a href="#dfn-list" title="list" class="tref internalDFN">list</a>.</li>
+ <li>A <a href="#dfn-node" title="node" class="tref internalDFN">node</a> having an outgoing edge <em title="must" class="rfc2119">must</em> be an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> or a
+ <a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">blank node</a>.</li>
+ <li>A <a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">JSON-LD graph</a> <em title="must not" class="rfc2119">must not</em> contain unconnected <a href="#dfn-node" title="node" class="tref internalDFN">nodes</a>,
+ i.e., nodes which are not connected by an <a href="#dfn-edge" title="edge" class="tref internalDFN">edge</a> to any other <a href="#dfn-node" title="node" class="tref internalDFN">node</a>.</li>
+ <li>An <dfn id="dfn-iri" title="iri"><abbr title="Internationalized Resource Identifier">IRI</abbr></dfn>
+ (Internationalized Resource Identifier) is a string that conforms to the syntax
+ defined in [<cite><a href="#bib-RFC3987" class="bibref">RFC3987</a></cite>]. <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a> used within a
+ <a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">JSON-LD graph</a> <em title="should" class="rfc2119">should</em> return a <a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">Linked Data</a> document describing
+ the resource denoted by that <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> when being dereferenced.</li>
+ <li>A <dfn id="dfn-blank-node" title="blank-node">blank node</dfn> is a <a href="#dfn-node" title="node" class="tref internalDFN">node</a> which is neither an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>,
+ nor a <a href="#dfn-json-ld-value" title="json-ld-value" class="tref internalDFN">JSON-LD value</a>, or a <a href="#dfn-list" title="list" class="tref internalDFN">list</a>. A blank node <em title="may" class="rfc2119">may</em> be identified
+ using a <a href="#dfn-blank-node-identifier" title="blank-node-identifier" class="tref internalDFN">blank node identifier</a>.</li>
+ <li>A <dfn id="dfn-blank-node-identifier" title="blank-node-identifier">blank node identifier</dfn> is a string that can be used as an identifier
+ for a <a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">blank node</a> within the scope of a <a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">JSON-LD document</a>.
+ Blank node identifiers begin with <code>_:</code>.</li>
+ <li>A <dfn id="dfn-json-ld-value" title="json-ld-value">JSON-LD value</dfn> is a <a href="#dfn-string" title="string" class="tref internalDFN">string</a>, a <a href="#dfn-number" title="number" class="tref internalDFN">number</a>,
+ <a href="#dfn-true" title="true" class="tref internalDFN">true</a> or <a href="#dfn-false" title="false" class="tref internalDFN">false</a>, a <a href="#dfn-typed-value" title="typed-value" class="tref internalDFN">typed value</a>, or a
+ <a href="#dfn-language-tagged-string" title="language-tagged-string" class="tref internalDFN">language-tagged string</a>.</li>
+ <li>A <dfn id="dfn-typed-value" title="typed-value">typed value</dfn> consists of a value, which is a string, and a type, which is an
+ <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>.</li>
+ <li>A <dfn id="dfn-language-tagged-string" title="language-tagged-string">language-tagged string</dfn> consists of a string and a non-empty language
+ tag as defined by [<cite><a href="#bib-BCP47" class="bibref">BCP47</a></cite>]. The language tag <em title="must" class="rfc2119">must</em> be well-formed according to section
+ <a href="http://tools.ietf.org/html/bcp47#section-2.2.9">2.2.9</a> of [<cite><a href="#bib-BCP47" class="bibref">BCP47</a></cite>], and <em title="must" class="rfc2119">must</em>
+ be lowercase.</li>
+ <li>A <dfn id="dfn-list" title="list">list</dfn> is an ordered sequence of zero or more
+ <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a>,
+ <a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">blank nodes</a>, and
+ <a href="#dfn-json-ld-value" title="json-ld-value" class="tref internalDFN">JSON-LD values</a>.</li>
+ </ul>
+
+ <div class="issue"><div class="issue-title"><a href="https://github.com/json-ld/json-ld.org/issues/217"><span>Issue 217</span></a></div><p class="">In contrast to the RDF data model as defined in [<cite><a href="#bib-RDF-CONCEPTS" class="bibref">RDF-CONCEPTS</a></cite>], JSON-LD allows
+ blank nodes as property labels and graph names. This feature is
+ controversial in the RDF WG and may be removed in the future.</p></div>
+
+ <p><a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">JSON-LD documents</a> <em title="may" class="rfc2119">may</em> contain data that cannot be
+ represented by the <a href="#dfn-json-ld-data-model" title="json-ld-data-model" class="tref internalDFN">data model</a> defined above.
+ Unless otherwise specified, such data is ignored when a <a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">JSON-LD document</a>
+ is being processed. This means, e.g., that properties which are not mapped to an
+ <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> or <a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">blank node</a> will be ignored.</p>
+
+ <p style="text-align: center"><img src="linked-data-graph.png" title="An illustration of JSON-LD's data model"></p>
+ <p style="text-align: center">Figure 1: An illustration of JSON-LD's data model.</p>
+</section>
+
+<section id="json-ld-grammar" class="appendix normative">
+<!--OddPage--><h2><span class="secno">B. </span>JSON-LD Grammar</h2>
+<em>This section is normative</em>
+
+
+<p>This appendix restates the syntactic conventions described in the
+ previous sections more formally.</p>
+
+<div class="note"><div class="note-title"><span>Note</span></div><p class="">The JSON-LD context allows <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keywords</a>
+ <a class="sec-ref" href="#aliasing-keywords"><span class="secno">6.14</span> <span class="sec-title">Aliasing Keywords</span></a>). Whenever a <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a> is
+ discussed in this grammar, the statements also apply to an alias for
+ that <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a>. For example, if the <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a>
+ defines the <a href="#dfn-term" title="term" class="tref internalDFN">term</a> <code>id</code> as an alias for <code>@id</code>,
+ that alias may be legitimately used as a substitution for <code>@id</code>.
+ Note that <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a> aliases are not expanded during context
+ processing.</p></div>
+
+<p>A <a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">JSON-LD document</a> <em title="must" class="rfc2119">must</em> be a valid JSON document as described
+ in [<cite><a href="#bib-RFC4627" class="bibref">RFC4627</a></cite>].</p>
+
+<p>A <a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">JSON-LD document</a> <em title="must" class="rfc2119">must</em> be a single <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a>
+ or a JSON <a href="#dfn-array" title="array" class="tref internalDFN">array</a> containing a set of one or more
+ <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node objects</a>.</p>
+
+<section rel="bibo:chapter" resource="#grammar-node-object" typeof="bibo:Chapter" id="grammar-node-object">
+<h3><span class="secno">B.1 </span>Node Object</h3>
+
+<p>A <dfn id="dfn-node-object" title="node-object">node object</dfn> represents zero or more properties of a
+ <a href="#dfn-node" title="node" class="tref internalDFN">node</a> in the <a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">JSON-LD graph</a> serialized by the
+ <a href="#dfn-json-ld-document" title="json-ld-document" class="tref internalDFN">JSON-LD document</a>. A <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a> is a
+ <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a> if it exists outside of a JSON-LD
+ <a href="#dfn-context" title="context" class="tref internalDFN">context</a> and:</p>
+
+<ul>
+ <li>it does not contain the <code>@value</code>, <code>@list</code>,
+ or <code>@set</code> keywords, and</li>
+ <li>it is not the top-most <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a> in the JSON-LD document
+ consisting of no other members than <code>@graph</code> and
+ <code>@context</code>.
+</li></ul>
+
+<p>The <a href="#dfn-property" title="property" class="tref internalDFN">properties</a> of a <a href="#dfn-node" title="node" class="tref internalDFN">node</a> in
+ a <a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">JSON-LD graph</a> may be spread among different
+ <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node objects</a> within a document. When
+ that happens, the keys of the different
+ <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node objects</a> are merged to create the
+ properties of the resulting <a href="#dfn-node" title="node" class="tref internalDFN">node</a>.</p>
+
+<p>A <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a> <em title="must" class="rfc2119">must</em> be a <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a>. All keys
+ which are not <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a>,
+ <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact IRIs</a>, <a href="#dfn-term" title="term" class="tref internalDFN">terms</a>
+ valid in the <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a>, or one of the following
+ <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keywords</a> <em title="must" class="rfc2119">must</em> be ignored when processed:</p>
+
+<ul>
+ <li><code>@context</code>,</li>
+ <li><code>@graph</code>,</li>
+ <li><code>@id</code>,</li>
+ <li><code>@type</code>, or</li>
+ <li><code>@index</code></li>
+</ul>
+
+<p>If the <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a> contains the <code>@context</code>
+ key, its value <em title="must" class="rfc2119">must</em> be one of the following:</p>
+<ul>
+ <li><a href="#dfn-null" title="null" class="tref internalDFN">null</a>,</li>
+ <li>an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>,</li>
+ <li>a <a href="#dfn-context-definition" title="context-definition" class="tref internalDFN">context definition</a>, or</li>
+ <li>an <a href="#dfn-array" title="array" class="tref internalDFN">array</a> composed of any number of the previous two expressions.</li>
+</ul>
+
+<p>If the <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a> contains the <code>@id</code> key,
+ its value <em title="must" class="rfc2119">must</em> be an <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a>, a <a href="#dfn-relative-iri" title="relative-iri" class="tref internalDFN">relative <abbr title="Internationalized Resource Identifier">IRI</abbr></a>,
+ or a <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact <abbr title="Internationalized Resource Identifier">IRI</abbr></a> (including
+ <a href="#dfn-blank-node-identifier" title="blank-node-identifier" class="tref internalDFN">blank node identifiers</a>).
+ See <a class="sec-ref" href="#node-identifiers"><span class="secno">5.3</span> <span class="sec-title">Node Identifiers</span></a>, <a class="sec-ref" href="#compact-iris"><span class="secno">6.1</span> <span class="sec-title">Compact IRIs</span></a>,
+ and <a class="sec-ref" href="#identifying-blank-nodes"><span class="secno">6.13</span> <span class="sec-title">Identifying Blank Nodes</span></a> for further discussion on
+ <code>@id</code> values.</p>
+
+<p>If the <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a> contains the <code>@type</code>
+ key, its value <em title="must" class="rfc2119">must</em> be either an <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a>, a
+ <a href="#dfn-relative-iri" title="relative-iri" class="tref internalDFN">relative <abbr title="Internationalized Resource Identifier">IRI</abbr></a>, a <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact <abbr title="Internationalized Resource Identifier">IRI</abbr></a>
+ (including <a href="#dfn-blank-node-identifier" title="blank-node-identifier" class="tref internalDFN">blank node identifiers</a>),
+ a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> defined in the <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a> expanding into an <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a>, or
+ an <a href="#dfn-array" title="array" class="tref internalDFN">array</a> of any of these.
+ See <a class="sec-ref" href="#specifying-the-type"><span class="secno">5.4</span> <span class="sec-title">Specifying the Type</span></a> for further discussion on
+ <code>@type</code> values.</p>
+
+<p>If the <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a> contains the <code>@graph</code>
+ key, its value <em title="must" class="rfc2119">must</em> be
+ a <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a> or
+ an <a href="#dfn-array" title="array" class="tref internalDFN">array</a> of zero or more <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node objects</a>.
+ If the <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a> contains an <code>@id</code> keyword,
+ its value is used as the label of a named graph.
+ See <a class="sec-ref" href="#named-graphs"><span class="secno">6.12</span> <span class="sec-title">Named Graphs</span></a> for further discussion on
+ <code>@graph</code> values. As a special case, if a <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a>
+ contains no keys other than <code>@graph</code> and <code>@context</code>, and the
+ <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a> is the root of the JSON-LD document, the
+ <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a> is not treated as a <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a>; this
+ is used as a way of defining <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node
+ definitions</a> that may not form a connected graph. This allows a
+ <a href="#dfn-context" title="context" class="tref internalDFN">context</a> to be defined which is shared by all of the constituent
+ <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node objects</a>.</p>
+
+<p>If the <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a> contains the <code>@index</code> key,
+ its value <em title="must" class="rfc2119">must</em> be a <a href="#dfn-string" title="string" class="tref internalDFN">string</a>. See section
+ <a class="sec-ref" href="#data-indexing"><span class="secno">6.17</span> <span class="sec-title">Data Indexing</span></a> for further discussion on <code>@index</code>
+ values.</p>
+
+
+<p>Keys in a <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a> that are not
+ <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keywords</a> <em title="must" class="rfc2119">must</em> expand to an <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a>
+ using the <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a>. The values associated with these keys
+ <em title="must" class="rfc2119">must</em> be one of the following:</p>
+
+<ul>
+ <li><a href="#dfn-string" title="string" class="tref internalDFN">string</a>,</li>
+ <li><a href="#dfn-number" title="number" class="tref internalDFN">number</a>,</li>
+ <li><a href="#dfn-true" title="true" class="tref internalDFN">true</a>,</li>
+ <li><a href="#dfn-false" title="false" class="tref internalDFN">false</a>,</li>
+ <li><a href="#dfn-null" title="null" class="tref internalDFN">null</a>,</li>
+ <li><a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a>,</li>
+ <li><a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">expanded value</a>,</li>
+ <li><a href="#dfn-list" title="list" class="tref internalDFN">list</a> or <a href="#dfn-set" title="set" class="tref internalDFN">set</a>,</li>
+ <li>an <a href="#dfn-array" title="array" class="tref internalDFN">array</a> of zero or more of the possibilities above,</li>
+ <li>a <a href="#dfn-language-map" title="language-map" class="tref internalDFN">language map</a>, or </li>
+ <li>an <a href="#dfn-index-map" title="index-map" class="tref internalDFN">index map</a></li>
+</ul>
+
+</section>
+
+<section rel="bibo:chapter" resource="#grammar-term-reference" typeof="bibo:Chapter" id="grammar-term-reference">
+ <h3><span class="secno">B.2 </span>Term</h3>
+ <p>A <dfn id="dfn-term" title="term">term</dfn> is a short-hand <a href="#dfn-string" title="string" class="tref internalDFN">string</a> that expands
+ to an <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a> or a <a href="#dfn-blank-node-identifier" title="blank-node-identifier" class="tref internalDFN">blank node identifier</a>.</p>
+
+ <p>A <a href="#dfn-term" title="term" class="tref internalDFN">term</a> <em title="must not" class="rfc2119">must not</em> equal any of the JSON-LD
+ <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keywords</a>.</p>
+
+ <p>To avoid forward-compatibility issues, a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> <em title="should not" class="rfc2119">should not</em> start
+ with an <code>@</code> character as future versions of JSON-LD may introduce
+ additional <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keywords</a>. Furthermore, the use of
+ empty terms (<code>""</code>) is discouraged as not all programming languages
+ are able to handle empty property names.</p>
+
+ <p>See <a class="sec-ref" href="#the-context"><span class="secno">5.1</span> <span class="sec-title">The Context</span></a> and <a class="sec-ref" href="#iris"><span class="secno">5.2</span> <span class="sec-title">IRIs</span></a> for further discussion
+ on mapping <a href="#dfn-term" title="term" class="tref internalDFN">terms</a> to <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a>.</p>
+</section>
+
+<section rel="bibo:chapter" resource="#grammar-language-map" typeof="bibo:Chapter" id="grammar-language-map">
+<h3><span class="secno">B.3 </span>Language Map</h3>
+<p>A <dfn id="dfn-language-map" title="language-map">language map</dfn> is used to associate a language with a value in a
+ way that allows easy programmatic access. A <a href="#dfn-language-map" title="language-map" class="tref internalDFN">language map</a> may be
+ used as a term value within a <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a> if the term is defined
+ with <code>@container</code> set to <code>@language</code>. The keys of a
+ <a href="#dfn-language-map" title="language-map" class="tref internalDFN">language map</a> <em title="must" class="rfc2119">must</em> be lowercase [<cite><a href="#bib-BCP47" class="bibref">BCP47</a></cite>]
+ <a href="#dfn-string" title="string" class="tref internalDFN">strings</a> with an associated value that is any
+ of the following types:</p>
+<ul>
+ <li><a href="#dfn-string" title="string" class="tref internalDFN">string</a>, or</li>
+ <li>an <a href="#dfn-array" title="array" class="tref internalDFN">array</a> of zero or more strings</li>
+</ul>
+<p>See <a href="#language-tagged-strings"></a> for further discussion on language maps.</p>
+</section>
+
+<section rel="bibo:chapter" resource="#grammar-index-map" typeof="bibo:Chapter" id="grammar-index-map">
+<h3><span class="secno">B.4 </span>Index Map</h3>
+<p>An <dfn id="dfn-index-map" title="index-map">index map</dfn> allows keys that have no semantic meaning,
+ but should be preserved regardless, to be used in JSON-LD documents.
+ An <a href="#dfn-index-map" title="index-map" class="tref internalDFN">index map</a> may
+ be used as a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> value within a <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a> if the
+ term is defined with <code>@container</code> set to <code>@index</code>.
+ The values of the members of an <a href="#dfn-index-map" title="index-map" class="tref internalDFN">index map</a> <em title="must" class="rfc2119">must</em> be one
+ of the following types:</p>
+<ul>
+ <li><a href="#dfn-string" title="string" class="tref internalDFN">string</a>,</li>
+ <li><a href="#dfn-number" title="number" class="tref internalDFN">number</a>,</li>
+ <li><a href="#dfn-true" title="true" class="tref internalDFN">true</a>,</li>
+ <li><a href="#dfn-false" title="false" class="tref internalDFN">false</a>,</li>
+ <li><a href="#dfn-null" title="null" class="tref internalDFN">null</a>,</li>
+ <li><a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a>,</li>
+ <li><a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">expanded value</a>,</li>
+ <li>an <a href="#dfn-array" title="array" class="tref internalDFN">array</a> of zero or more of the above possibilities</li>
+</ul>
+<p>See <a class="sec-ref" href="#data-indexing"><span class="secno">6.17</span> <span class="sec-title">Data Indexing</span></a> for further information on this
+topic.</p>
+</section>
+
+<section rel="bibo:chapter" resource="#grammar-expanded-values" typeof="bibo:Chapter" id="grammar-expanded-values">
+<h3><span class="secno">B.5 </span>Expanded Values</h3>
+
+<p>An <dfn id="dfn-expanded-value" title="expanded-value">expanded value</dfn> is used to explicitly associate a type or a
+ language with a value to create a <a href="#dfn-typed-value" title="typed-value" class="tref internalDFN">typed value</a> or a <a href="#dfn-language-tagged-string" title="language-tagged-string" class="tref internalDFN">language-tagged
+ string</a>.</p>
+
+<p>An <a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">expanded value</a> <em title="must" class="rfc2119">must</em> be a <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a> containing the
+ <code>@value</code> key. It <em title="may" class="rfc2119">may</em> also contain a <code>@type</code>,
+ a <code>@language</code>, or an <code>@index</code> key but <em title="must not" class="rfc2119">must not</em> contain
+ both a <code>@type</code> and a <code>@language</code> key at the same time.
+ An <a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">expanded value</a> <em title="must not" class="rfc2119">must not</em> contain keys other than
+ <code>@value</code>, <code>@type</code>, <code>@language</code>, and
+ <code>@index</code>. An <a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">expanded value</a> that contains a
+ <code>@type</code> key is called an <dfn id="dfn-expanded-typed-value" title="expanded-typed-value">expanded typed value</dfn>.
+ An <a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">expanded value</a> that contains a <code>@language</code> key
+ is called an <dfn id="dfn-expanded-language-tagged-string" title="expanded-language-tagged-string">expanded language-tagged string</dfn>.</p>
+
+<p>The value associated with the <code>@value</code> key <em title="must" class="rfc2119">must</em> be either a
+ <a href="#dfn-string" title="string" class="tref internalDFN">string</a>, <a href="#dfn-number" title="number" class="tref internalDFN">number</a>, <a href="#dfn-true" title="true" class="tref internalDFN">true</a>,
+ <a href="#dfn-false" title="false" class="tref internalDFN">false</a> or <a href="#dfn-null" title="null" class="tref internalDFN">null</a>.</p>
+
+<p>The value associated with the <code>@type</code> key <em title="must" class="rfc2119">must</em> be a
+ <a href="#dfn-term" title="term" class="tref internalDFN">term</a>, a <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact <abbr title="Internationalized Resource Identifier">IRI</abbr></a>,
+ an <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a>, a <a href="#dfn-relative-iri" title="relative-iri" class="tref internalDFN">relative <abbr title="Internationalized Resource Identifier">IRI</abbr></a>, or <a href="#dfn-null" title="null" class="tref internalDFN">null</a>.</p>
+
+<p>The value associated with the <code>@language</code> key <em title="must" class="rfc2119">must</em> have the
+ lexical form described in [<cite><a href="#bib-BCP47" class="bibref">BCP47</a></cite>], or be <a href="#dfn-null" title="null" class="tref internalDFN">null</a>.</p>
+
+<p>The value associated with the <code>@index</code> key <em title="must" class="rfc2119">must</em> be a
+ <a href="#dfn-string" title="string" class="tref internalDFN">string</a>.</p>
+
+<p>See <a class="sec-ref" href="#typed-values"><span class="secno">6.2</span> <span class="sec-title">Typed Values</span></a> and <a href="#language-tagged-strings"></a>
+ for more information on
+ <a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">expanded values</a>.</p>
+</section>
+
+<section rel="bibo:chapter" resource="#grammar-set-list" typeof="bibo:Chapter" id="grammar-set-list">
+<h3><span class="secno">B.6 </span>List and Set Values</h3>
+
+<p>A <a href="#dfn-list" title="list" class="tref internalDFN">list</a> represents an <em>ordered</em> set of values. A <dfn id="dfn-set" title="set">set</dfn>
+ represents an <em>unordered</em> set of values. Unless otherwise specified,
+ <a href="#dfn-array" title="array" class="tref internalDFN">arrays</a> are unordered in JSON-LD. As such, the
+ <code>@set</code> keyword, when used in the body of a JSON-LD document,
+ represents just syntactic sugar which is optimized away when processing the document.
+ However, it is very helpful when used within the context of a document. Values
+ of terms associated with a <code>@set</code> or <code>@list</code> container
+ will always be represented in the form of an array when a document is processed -
+ even if there is just a single value that would otherwise be optimized to
+ a non-array form in <a href="#compact-document-form">compact document form</a>.
+ This simplifies post-processing of the data as the data is always in array form.</p>
+
+<p>A <a href="#dfn-list" title="list" class="tref internalDFN">list</a> <em title="must" class="rfc2119">must</em> be a <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a> that contains no other
+ keys than <code>@list</code>, <code>@context</code>, and <code>@index</code>.</p>
+
+<p>A <a href="#dfn-set" title="set" class="tref internalDFN">set</a> <em title="must" class="rfc2119">must</em> be a <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a> that that contains no other
+ keys than <code>@set</code>, <code>@context</code>, and <code>@index</code>.
+ Please note that the <code>@index</code> key will be ignored, and thus be dropped,
+ when being processed.</p>
+
+<p>In both cases, the value associated with the keys <code>@list</code> and <code>@set</code>
+ <em title="must" class="rfc2119">must</em> be an <a href="#dfn-array" title="array" class="tref internalDFN">array</a> of any of the following:</p>
+<ul>
+ <li><a href="#dfn-string" title="string" class="tref internalDFN">string</a>,</li>
+ <li><a href="#dfn-number" title="number" class="tref internalDFN">number</a>,</li>
+ <li><a href="#dfn-true" title="true" class="tref internalDFN">true</a>,</li>
+ <li><a href="#dfn-false" title="false" class="tref internalDFN">false</a>,</li>
+ <li><a href="#dfn-null" title="null" class="tref internalDFN">null</a>,</li>
+ <li><a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a>, or</li>
+ <li><a href="#dfn-expanded-value" title="expanded-value" class="tref internalDFN">expanded value</a></li>
+</ul>
+
+<p>See <a class="sec-ref" href="#sets-and-lists"><span class="secno">6.10</span> <span class="sec-title">Sets and Lists</span></a> for further discussion on List and Set Values.</p>
+</section>
+
+<section rel="bibo:chapter" resource="#grammar-context" typeof="bibo:Chapter" id="grammar-context">
+<h3><span class="secno">B.7 </span>Context Definition</h3>
+<p>A <dfn id="dfn-context-definition" title="context-definition">context definition</dfn> defines a <a href="#dfn-local-context" title="local-context" class="tref internalDFN">local context</a> in a <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a>.</p>
+
+<p>A <a href="#dfn-context-definition" title="context-definition" class="tref internalDFN">context definition</a> <em title="must" class="rfc2119">must</em> be a <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a>
+ containing one or more key-value pairs. Keys <em title="must" class="rfc2119">must</em> either be
+ <a href="#dfn-term" title="term" class="tref internalDFN">terms</a> or <code>@language</code> or <code>@vocab</code> <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keywords</a>.
+
+</p><p>If the <a href="#dfn-context-definition" title="context-definition" class="tref internalDFN">context definition</a> has a <code>@language</code> key,
+ its value <em title="must" class="rfc2119">must</em> have the lexical form described in [<cite><a href="#bib-BCP47" class="bibref">BCP47</a></cite>] or be <a href="#dfn-null" title="null" class="tref internalDFN">null</a>.</p>
+<p>If the <a href="#dfn-context-definition" title="context-definition" class="tref internalDFN">context definition</a> has a <code>@vocab</code> key,
+ its value <em title="must" class="rfc2119">must</em> have the lexical form of <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a> or be <a href="#dfn-null" title="null" class="tref internalDFN">null</a>.</p>
+
+<p><a href="#dfn-term" title="term" class="tref internalDFN">Term</a> values <em title="must" class="rfc2119">must</em> be either a
+ <a href="#dfn-string" title="string" class="tref internalDFN">string</a>, <a href="#dfn-null" title="null" class="tref internalDFN">null</a>, or an <a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">expanded term definition</a>.</p>
+
+<p>An <a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">expanded term definition</a> is used to describe the mapping
+ between a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> and its expanded identifier, as well as other
+ properties of the value associated with the <a href="#dfn-term" title="term" class="tref internalDFN">term</a> when it is
+ used as key in a <a href="#dfn-node-object" title="node-object" class="tref internalDFN">node object</a>.</p>
+
+<p>An <a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">expanded term definition</a> <em title="should" class="rfc2119">should</em> be a <a href="#dfn-json-object" title="json-object" class="tref internalDFN">JSON object</a>
+ composed of zero or more keys from <code>@id</code>,
+ <code>@type</code>, <code>@language</code> or <code>@container</code>. An
+ <a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">expanded term definition</a> <em title="should not" class="rfc2119">should not</em> contain any other keys.
+</p><p>If the <a href="#dfn-term" title="term" class="tref internalDFN">term</a> definition is not <a href="#dfn-null" title="null" class="tref internalDFN">null</a>, a <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact <abbr title="Internationalized Resource Identifier">IRI</abbr></a>,
+ or an <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a> and the <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a> does not have an
+ <code>@vocab</code> mapping, the <a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">expanded term definition</a> <em title="must" class="rfc2119">must</em>
+ include the <code>@id</code> key.</p>
+
+<p>If the <a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">expanded term definition</a> contains the <code>@id</code> <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a>,
+ its value <em title="must" class="rfc2119">must</em> be <a href="#dfn-null" title="null" class="tref internalDFN">null</a>, an <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a>, a <a href="#dfn-blank-node-identifier" title="blank-node-identifier" class="tref internalDFN">blank node identifier</a>,
+ a <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact <abbr title="Internationalized Resource Identifier">IRI</abbr></a>, a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> defined in the defining <a href="#dfn-context-definition" title="context-definition" class="tref internalDFN">context definition</a>
+ or the <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a>, or an <a href="#dfn-array" title="array" class="tref internalDFN">array</a> composed of any of the previous allowed values except
+ <a href="#dfn-null" title="null" class="tref internalDFN">null</a>.</p>
+<p>If the <a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">expanded term definition</a> contains the <code>@type</code> <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a>,
+ its value <em title="must" class="rfc2119">must</em> be an <a href="#dfn-absolute-iri" title="absolute-iri" class="tref internalDFN">absolute <abbr title="Internationalized Resource Identifier">IRI</abbr></a>, a <a href="#dfn-compact-iri" title="compact-iri" class="tref internalDFN">compact <abbr title="Internationalized Resource Identifier">IRI</abbr></a>, a <a href="#dfn-term" title="term" class="tref internalDFN">term</a> defined in the
+ defining <a href="#dfn-context-definition" title="context-definition" class="tref internalDFN">context definition</a> or the <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a>, <a href="#dfn-null" title="null" class="tref internalDFN">null</a>, or the one of the
+ <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keywords</a> <code>@id</code> or <code>@vocab</code>.</p>
+<p>If the <a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">expanded term definition</a> contains the <code>@language</code> <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a>,
+ its value <em title="must" class="rfc2119">must</em> have the lexical form described in [<cite><a href="#bib-BCP47" class="bibref">BCP47</a></cite>] or be <a href="#dfn-null" title="null" class="tref internalDFN">null</a>.</p>
+<p>If the <a href="#dfn-expanded-term-definition" title="expanded-term-definition" class="tref internalDFN">expanded term definition</a> contains the <code>@container</code> <a href="#dfn-keyword" title="keyword" class="tref internalDFN">keyword</a>,
+ its value <em title="must" class="rfc2119">must</em> be either <code>@list</code>, <code>@set</code>, <code>@language</code>, <code>@index</code>, or be <a href="#dfn-null" title="null" class="tref internalDFN">null</a>.
+ If the value is <code>@language</code>, when the <a href="#dfn-term" title="term" class="tref internalDFN">term</a> is used outside of the <code>@context</code>, the
+ associated value <em title="must" class="rfc2119">must</em> be a <a href="#dfn-language-map" title="language-map" class="tref internalDFN">language map</a>. If the value is
+ <code>@index</code>, when the <a href="#dfn-term" title="term" class="tref internalDFN">term</a> is used outside of
+ the <code>@context</code>, the associated value <em title="must" class="rfc2119">must</em> be an
+ <a href="#dfn-index-map" title="index-map" class="tref internalDFN">index map</a>.</p>
+
+<p><a href="#dfn-term" title="term" class="tref internalDFN">Terms</a> <em title="must not" class="rfc2119">must not</em> be used in a circular manner. That is, the definition of a term cannot depend on the definition of another term if that other term also depends on the first term.</p>
+
+<p>See <a class="sec-ref" href="#the-context"><span class="secno">5.1</span> <span class="sec-title">The Context</span></a> for further discussion on contexts.</p>
+</section>
+
+</section>
+
+<section id="relationship-to-rdf" class="appendix normative">
+ <!--OddPage--><h2><span class="secno">C. </span>Relationship to RDF</h2>
+
+ <p>The RDF data model, as outlined in [<cite><a href="#bib-RDF-CONCEPTS" class="bibref">RDF-CONCEPTS</a></cite>], is an abstract syntax for
+ representing a directed graph of information. It is a subset of
+ <a href="#dfn-json-ld-data-model" title="json-ld-data-model" class="tref internalDFN">JSON-LD's data model</a> with a few
+ additional constraints. The differences between the two data models are:</p>
+
+ <ul>
+ <li>In JSON-LD <a href="#dfn-graph-name" title="graph-name" class="tref internalDFN">graph names</a> can be
+ <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a> or <a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">blank nodes</a>
+ whereas in RDF graph names have to be <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a>.</li>
+ <li>In JSON-LD <a href="#dfn-property" title="property" class="tref internalDFN">properties</a> can be
+ <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a> or <a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">blank nodes</a>
+ whereas in RDF properties (predicates) have to be
+ <a href="#dfn-iri" title="iri" class="tref internalDFN">IRIs</a>.</li>
+ <li>In JSON-LD lists are part of the data model whereas in RDF they are part of
+ a vocabulary, namely [<cite><a href="#bib-RDF-SCHEMA" class="bibref">RDF-SCHEMA</a></cite>].</li>
+ <li>RDF values are either typed <em>literals</em>
+ (<a href="#dfn-typed-value" title="typed-value" class="tref internalDFN">typed values</a>) or <em>language-tagged strings</em>
+ (<a href="#dfn-language-tagged-string" title="language-tagged-string" class="tref internalDFN">language-tagged strings</a>) whereas
+ JSON-LD also supports JSON's native data types, i.e., <a href="#dfn-number" title="number" class="tref internalDFN">number</a>,
+ <a href="#dfn-string" title="string" class="tref internalDFN">strings</a>, and the boolean values <a href="#dfn-true" title="true" class="tref internalDFN">true</a>
+ and <a href="#dfn-false" title="false" class="tref internalDFN">false</a>. The JSON-LD Algorithms and API specification [<cite><a href="#bib-JSON-LD-API" class="bibref">JSON-LD-API</a></cite>] defines
+ the conversion rules between JSON's native data types and RDF's counterparts to
+ allow full round-tripping.</li>
+
+ </ul>
+
+ <p>Summarized these differences mean that JSON-LD is capable of serializing any RDF
+ graph or dataset and most, but not all, JSON-LD documents can be transformed to RDF.
+ A complete description of the algorithms to convert from RDF to JSON-LD and from
+ JSON-LD to RDF is included in the JSON-LD Algorithms and API specification
+ [<cite><a href="#bib-JSON-LD-API" class="bibref">JSON-LD-API</a></cite>].</p>
+
+ <p>Even though JSON-LD serializes RDF datasets, it can also be used as a RDF graph source.
+ In that case, a consumer <em title="must" class="rfc2119">must</em> only use the default graph and ignore all named graphs.
+ This allows servers to expose data in, e.g., both Turtle and JSON-LD using content
+ negotiation.</p>
+
+ <div class="note"><div class="note-title"><span>Note</span></div><p class="">Publishers supporting both dataset and graph syntaxes have to ensure that
+ the primary data is stored in the default graph to enable consumers that do not support
+ datasets to process the information.</p></div>
+</section>
+
+<section id="relationship-to-other-linked-data-formats" class="appendix informative">
+<!--OddPage--><h2><span class="secno">D. </span>Relationship to Other Linked Data Formats</h2><p><em>This section is non-normative.</em></p>
+
+<p>The JSON-LD markup examples below demonstrate how JSON-LD can be used to
+ express semantic data marked up in other linked data formats such as Turtle,
+ RDFa, Microformats, and Microdata. These sections are merely provided as
+ evidence that JSON-LD is very flexible in what it can express across different
+ <a href="#dfn-linked-data" title="linked-data" class="tref internalDFN">Linked Data</a> approaches.</p>
+
+<section id="turtle">
+ <h3><span class="secno">D.1 </span>Turtle</h3><p><em>This section is non-normative.</em></p>
+
+ <p>The following are examples of converting RDF expressed in Turtle [<cite><a href="#bib-TURTLE-TR" class="bibref">TURTLE-TR</a></cite>]
+ into JSON-LD.</p>
+
+<section id="prefix-definitions">
+<h4><span class="secno">D.1.1 </span>Prefix definitions</h4><p><em>This section is non-normative.</em></p>
+<p>The JSON-LD context has direct equivalents for the Turtle
+ <code>@prefix</code> declaration:</p>
+
+<div class="example"><div class="example-title"><span>Example 57</span>: A set of statements serialized in Turtle</div><pre class="example">@prefix foaf: <http://xmlns.com/foaf/0.1/> .
+
+<http://manu.sporny.org/i/public> a foaf:Person;
+ foaf:name "Manu Sporny";
+ foaf:homepage <http://manu.sporny.org/> .</pre></div>
+
+<div class="example"><div class="example-title"><span>Example 58</span>: The same set of statements serialized in JSON-LD</div><pre class="example">{
+ "@context":
+ {
+ "foaf": "http://xmlns.com/foaf/0.1/"
+ },
+ "@id": "http://manu.sporny.org/i/public",
+ "@type": "foaf:Person",
+ "foaf:name": "Manu Sporny",
+ "foaf:homepage": { "@id": "http://manu.sporny.org/" }
+}</pre></div>
+
+<div class="note"><div class="note-title"><span>Note</span></div><p class="">JSON-LD has no equivalent for the Turtle <code>@base</code>
+declaration, but can use a prefix such as <code>base</code> to encode the
+information in the document.</p></div>
+
+</section>
+
+<section id="embedding-1">
+<h4><span class="secno">D.1.2 </span>Embedding</h4>
+<p>Both Turtle and JSON-LD allow embedding, although Turtle only allows embedding of
+ <a href="#dfn-blank-node" title="blank-node" class="tref internalDFN">blank nodes</a>.</p>
+</section>
+
+<div class="example"><div class="example-title"><span>Example 59</span>: Embedding in Turtle</div><pre class="example">@prefix foaf: <http://xmlns.com/foaf/0.1/> .
+
+<http://manu.sporny.org/i/public>
+ a foaf:Person;
+ foaf:name "Manu Sporny";
+ foaf:knows [ a foaf:Person; foaf:name "Gregg Kellogg" ] .</pre></div>
+
+<div class="example"><div class="example-title"><span>Example 60</span>: Same embedding example in JSON-LD</div><pre class="example">{
+ "@context":
+ {
+ "foaf": "http://xmlns.com/foaf/0.1/"
+ },
+ "@id": "http://manu.sporny.org/i/public",
+ "@type": "foaf:Person",
+ "foaf:name": "Manu Sporny",
+ "foaf:knows":
+ {
+ "@type": "foaf:Person",
+ "foaf:name": "Gregg Kellogg"
+ }
+}</pre></div>
+<section id="lists">
+<h4><span class="secno">D.1.3 </span>Lists</h4>
+<p>Both JSON-LD and Turtle can represent sequential lists of values.</p>
+
+<div class="example"><div class="example-title"><span>Example 61</span>: A list of values in Turtle</div><pre class="example">@prefix foaf: <http://xmlns.com/foaf/0.1/> .
+
+<http://example.org/people#joebob> a foaf:Person;
+ foaf:name "Joe Bob";
+ foaf:nick ( "joe" "bob" "jaybee" ) .</pre></div>
+
+<div class="example"><div class="example-title"><span>Example 62</span>: Same example with a list of values in JSON-LD</div><pre class="example">{
+ "@context":
+ {
+ "foaf": "http://xmlns.com/foaf/0.1/"
+ },
+ "@id": "http://example.org/people#joebob",
+ "@type": "foaf:Person",
+ "foaf:name": "Joe Bob",
+ "foaf:nick":
+ {
+ "@list": [ "joe", "bob", "jaybee" ]
+ }
+}</pre></div>
+</section>
+
+</section>
+
+<section id="rdfa">
+<h3><span class="secno">D.2 </span>RDFa</h3>
+
+<p>The following example describes three people with their respective names and
+ homepages in RDFa [<cite><a href="#bib-RDFA-CORE" class="bibref">RDFA-CORE</a></cite>].</p>
+
+<div class="example"><div class="example-title"><span>Example 63</span>: RDFa fragment that describes three people</div><pre class="example"><div <span class="diff">prefix="foaf: http://xmlns.com/foaf/0.1/"</span>>
+ <ul>
+ <li <span class="diff">typeof="foaf:Person"</span>>
+ <a <span class="diff">rel="foaf:homepage" href="http://example.com/bob/" property="foaf:name"</span>>Bob</a>
+ </li>
+ <li <span class="diff">typeof="foaf:Person"</span>>
+ <a <span class="diff">rel="foaf:homepage" href="http://example.com/eve/" property="foaf:name"</span>>Eve</a>
+ </li>
+ <li <span class="diff">typeof="foaf:Person"</span>>
+ <a <span class="diff">rel="foaf:homepage" href="http://example.com/manu/" property="foaf:name"</span>>Manu</a>
+ </li>
+ </ul>
+</div></pre></div>
+
+<p>An example JSON-LD implementation using a single <a href="#dfn-context" title="context" class="tref internalDFN">context</a> is
+ described below.</p>
+
+<div class="example"><div class="example-title"><span>Example 64</span>: Same description in JSON-LD (context shared among node objects)</div><pre class="example">{
+ "@context":
+ {
+ "foaf": "http://xmlns.com/foaf/0.1/"
+ },
+ "@graph":
+ [
+ {
+ "@type": "foaf:Person",
+ "foaf:homepage": "http://example.com/bob/",
+ "foaf:name": "Bob"
+ },
+ {
+ "@type": "foaf:Person",
+ "foaf:homepage": "http://example.com/eve/",
+ "foaf:name": "Eve"
+ },
+ {
+ "@type": "foaf:Person",
+ "foaf:homepage": "http://example.com/manu/",
+ "foaf:name": "Manu"
+ }
+ ]
+}</pre></div>
+
+</section>
+
+<section id="microformats">
+<h3><span class="secno">D.3 </span>Microformats</h3>
+
+<p>The following example uses a simple Microformats hCard example to express
+ how Microformats [<cite><a href="#bib-MICROFORMATS" class="bibref">MICROFORMATS</a></cite>] are represented in JSON-LD.</p>
+
+<div class="example"><div class="example-title"><span>Example 65</span>: HTML fragment with a simple Microformats hCard</div><pre class="example"><div class="vcard">
+ <a class="url fn" href="http://tantek.com/">Tantek Çelik</a>
+</div></pre></div>
+
+<p>The representation of the hCard expresses the Microformat terms in the
+ <a href="#dfn-context" title="context" class="tref internalDFN">context</a> and uses them directly for the <code>url</code> and <code>fn</code>
+ properties. Also note that the Microformat to JSON-LD processor has
+ generated the proper URL type for <code>http://tantek.com/</code>.</p>
+
+<div class="example"><div class="example-title"><span>Example 66</span>: Same hCard representation in JSON-LD</div><pre class="example">{
+ "@context":
+ {
+ "vcard": "http://microformats.org/profile/hcard#vcard",
+ "url":
+ {
+ "@id": "http://microformats.org/profile/hcard#url",
+ "@type": "@id"
+ },
+ "fn": "http://microformats.org/profile/hcard#fn"
+ },
+ "@type": "vcard",
+ "url": "http://tantek.com/",
+ "fn": "Tantek Çelik"
+}</pre></div>
+
+</section>
+
+<section id="microdata">
+<h3><span class="secno">D.4 </span>Microdata</h3>
+
+<p>The HTML Microdata [<cite><a href="#bib-MICRODATA" class="bibref">MICRODATA</a></cite>] example below expresses book information as
+ a Microdata Work item.</p>
+
+<div class="example"><div class="example-title"><span>Example 67</span>: HTML fragments that describes a book using microdata</div><pre class="example"><dl itemscope
+ itemtype="http://purl.org/vocab/frbr/core#Work"
+ itemid="http://purl.oreilly.com/works/45U8QJGZSQKDH8N">
+ <dt>Title</dt>
+ <dd><cite itemprop="http://purl.org/dc/terms/title">Just a Geek</cite></dd>
+ <dt>By</dt>
+ <dd><span itemprop="http://purl.org/dc/terms/creator">Wil Wheaton</span></dd>
+ <dt>Format</dt>
+ <dd itemprop="http://purl.org/vocab/frbr/core#realization"
+ itemscope
+ itemtype="http://purl.org/vocab/frbr/core#Expression"
+ itemid="http://purl.oreilly.com/products/9780596007683.BOOK">
+ <link itemprop="http://purl.org/dc/terms/type" href="http://purl.oreilly.com/product-types/BOOK">
+ Print
+ </dd>
+ <dd itemprop="http://purl.org/vocab/frbr/core#realization"
+ itemscope
+ itemtype="http://purl.org/vocab/frbr/core#Expression"
+ itemid="http://purl.oreilly.com/products/9780596802189.EBOOK">
+ <link itemprop="http://purl.org/dc/terms/type" href="http://purl.oreilly.com/product-types/EBOOK">
+ Ebook
+ </dd>
+</dl></pre></div>
+
+<p>Note that the JSON-LD representation of the Microdata information stays
+ true to the desires of the Microdata community to avoid contexts and
+ instead refer to items by their full <a href="#dfn-iri" title="iri" class="tref internalDFN"><abbr title="Internationalized Resource Identifier">IRI</abbr></a>.</p>
+
+<div class="example"><div class="example-title"><span>Example 68</span>: Same book description in JSON-LD (avoiding contexts)</div><pre class="example">[
+ {
+ "@id": "http://purl.oreilly.com/works/45U8QJGZSQKDH8N",
+ "@type": "http://purl.org/vocab/frbr/core#Work",
+ "http://purl.org/dc/terms/title": "Just a Geek",
+ "http://purl.org/dc/terms/creator": "Whil Wheaton",
+ "http://purl.org/vocab/frbr/core#realization":
+ [
+ "http://purl.oreilly.com/products/9780596007683.BOOK",
+ "http://purl.oreilly.com/products/9780596802189.EBOOK"
+ ]
+ },
+ {
+ "@id": "http://purl.oreilly.com/products/9780596007683.BOOK",
+ "@type": "http://purl.org/vocab/frbr/core#Expression",
+ "http://purl.org/dc/terms/type": "http://purl.oreilly.com/product-types/BOOK"
+ },
+ {
+ "@id": "http://purl.oreilly.com/products/9780596802189.EBOOK",
+ "@type": "http://purl.org/vocab/frbr/core#Expression",
+ "http://purl.org/dc/terms/type": "http://purl.oreilly.com/product-types/EBOOK"
+ }
+]</pre></div>
+</section>
+</section>
+
+<section id="iana-considerations" class="appendix informative">
+<!--OddPage--><h2><span class="secno">E. </span>IANA Considerations</h2><p><em>This section is non-normative.</em></p>
+
+<p>This section is included merely for standards community review and will be
+ submitted to the Internet Engineering Steering Group if this specification
+ becomes a W3C Recommendation.</p>
+
+<h2 id="application-ld-json">application/ld+json</h2>
+<dl>
+ <dt>Type name:</dt>
+ <dd>application</dd>
+ <dt>Subtype name:</dt>
+ <dd>ld+json</dd>
+ <dt>Required parameters:</dt>
+ <dd>None</dd>
+ <dt>Optional parameters:</dt>
+ <dd>
+ <dl>
+ <dt><code>profile</code></dt>
+ <dd>
+ <p>A whitespace-separated list of IRIs identifying specific constraints
+ or conventions that apply to a JSON-LD document. A profile <em title="must not" class="rfc2119">must not</em> change
+ the semantics of the resource representation when processed without profile
+ knowledge, so that clients both with and without knowledge of a profiled
+ resource can safely use the same representation. The <code>profile</code>
+ parameter <em title="may" class="rfc2119">may</em> also be used by clients to express their preferences in the
+ content negotiation process. It is <em title="recommended" class="rfc2119">recommended</em> that profile IRIs are
+ dereferenceable and provide useful documentation at that <abbr title="Internationalized Resource Identifier">IRI</abbr>. For more
+ information and background please refer to [<cite><a href="#bib-PROFILE-LINK" class="bibref">PROFILE-LINK</a></cite>].</p>
+ <p>This specification defines four values for the <code>profile</code> parameter.
+ To request or specify Expanded JSON-LD document form, the <abbr title="Internationalized Resource Identifier">IRI</abbr>
+ <code>http://www.w3.org/ns/json-ld#expanded</code> <em title="should" class="rfc2119">should</em> be used.
+ To request or specify Expanded, Flattened JSON-LD document form, the <abbr title="Internationalized Resource Identifier">IRI</abbr>
+ <code>http://www.w3.org/ns/json-ld#expanded-flattened</code> <em title="should" class="rfc2119">should</em>
+ be used. To request or specify Compacted JSON-LD document form, the <abbr title="Internationalized Resource Identifier">IRI</abbr>
+ <code>http://www.w3.org/ns/json-ld#compacted</code> <em title="should" class="rfc2119">should</em> be used.
+ To request or specify Compacted, Flattened JSON-LD document form, the <abbr title="Internationalized Resource Identifier">IRI</abbr>
+ <code>http://www.w3.org/ns/json-ld#compacted-flattened</code> <em title="should" class="rfc2119">should</em> be used.
+ Please note that, according [<cite><a href="#bib-HTTP11" class="bibref">HTTP11</a></cite>], the value of the <code>profile</code>
+ parameter has to be enclosed in quotes (<code>"</code>) because it contains
+ special characters and, in some cases, whitespace.</p>
+ </dd>
+ </dl>
+ </dd>
+ <dt>Encoding considerations:</dt>
+ <dd>See RFC 6839, section 3.1.</dd>
+ <dt>Security considerations:</dt>
+ <dd>Since JSON-LD is intended to be a pure data exchange format for
+ directed graphs, the serialization <em title="should not" class="rfc2119">should not</em> be passed through a
+ code execution mechanism such as JavaScript's <code>eval()</code>
+ function to be parsed.<br>
+ JSON-LD contexts that are loaded from the Web over non-secure connections,
+ such as HTTP, run the risk of modifying the JSON-LD
+ <a href="#dfn-active-context" title="active-context" class="tref internalDFN">active context</a> in a way that could compromise security. It
+ is advised that any application that depends on a remote context for mission
+ critical purposes vet and cache the remote context before allowing the
+ system to use it.<br>
+ JSON-LD allows the substitution of long IRIs with short terms and the
+ compression of multiple properties into a single property generator. Therefore,
+ JSON-LD documents may expand enormously when processed and, in the worst case,
+ the resulting data might consume all of the recipient's resources. Applications
+ should treat any data with due skepticism.
+ </dd>
+ <dt>Interoperability considerations:</dt>
+ <dd>Not Applicable</dd>
+ <dt>Published specification:</dt>
+ <dd>The <a href="http://json-ld.org/spec/latest/">JSON-LD</a> specification.</dd>
+ <dt>Applications that use this media type:</dt>
+ <dd>Any programming environment that requires the exchange of
+ directed graphs. Implementations of JSON-LD have been created for
+ JavaScript, Python, Ruby, PHP, and C++.
+ </dd>
+ <dt>Additional information:</dt>
+ <dd>
+ <dl>
+ <dt>Magic number(s):</dt>
+ <dd>Not Applicable</dd>
+ <dt>File extension(s):</dt>
+ <dd>.jsonld</dd>
+ <dt>Macintosh file type code(s):</dt>
+ <dd>TEXT</dd>
+ </dl>
+ </dd>
+ <dt>Person & email address to contact for further information:</dt>
+ <dd>Manu Sporny <msporny@digitalbazaar.com></dd>
+ <dt>Intended usage:</dt>
+ <dd>Common</dd>
+ <dt>Restrictions on usage:</dt>
+ <dd>None</dd>
+ <dt>Author(s):</dt>
+ <dd>Manu Sporny, Dave Longley, Gregg Kellogg, Markus Lanthaler, Niklas Lindström</dd>
+ <dt>Change controller:</dt>
+ <dd>W3C</dd>
+</dl>
+
+<p>Fragment identifiers used with <a href="#application-ld-json">application/ld+json</a>
+ resources <em title="may" class="rfc2119">may</em> identify a node in a <a href="#dfn-json-ld-graph" title="json-ld-graph" class="tref internalDFN">JSON-LD graph</a> expressed in
+ the resource. This idiom, which is also used in RDF [<cite><a href="#bib-RDF-CONCEPTS" class="bibref">RDF-CONCEPTS</a></cite>], gives a
+ simple way to "mint" new, document-local IRIs to label nodes and therefore contributes
+ considerably to the expressive power of JSON-LD.</p>
+
+</section>
+
+<section id="acknowledgements" class="appendix informative">
+ <!--OddPage--><h2><span class="secno">F. </span>Acknowledgements</h2><p><em>This section is non-normative.</em></p>
+
+ <p>The authors would like to extend a deep appreciation and the most sincere
+ thanks to Mark Birbeck, who contributed foundational concepts
+ to JSON-LD via his work on RDFj. JSON-LD uses a number of core concepts
+ introduced in RDFj, such as the context as a mechanism to provide an
+ environment for interpreting JSON data. Mark had also been very involved in
+ the work on RDFa as well. RDFj built upon that work. JSON-LD exists
+ because of the work and ideas he started nearly a decade ago in 2004.</p>
+
+ <p>A large amount of thanks goes out to the JSON-LD Community Group
+ participants who worked through many of the technical issues on the mailing
+ list and the weekly telecons - of special mention are François Daoust,
+ Stéphane Corlosquet, Lin Clark, and Zdenko 'Denny' Vrandečić.</p>
+
+ <p>The work of David I. Lehn and Mike Johnson are appreciated for
+ reviewing, and performing several early implementations
+ of the specification. Thanks also to Ian Davis for this work on RDF/JSON.</p>
+
+ <p>Thanks to the following individuals, in order of their first name, for
+ their input on the specification: Adrian Walker, Alexandre Passant,
+ Andy Seaborne, Ben Adida, Blaine Cook, Bradley Allen, Brian Peterson,
+ Bryan Thompson, Conal Tuohy, Dan Brickley, Danny Ayers, Daniel Leja,
+ Dave Reynolds, David I. Lehn, David Wood, Dean Landolt, Ed Summers, elf Pavlik,
+ Eric Prud'hommeaux, Erik Wilde, Fabian Christ, Jon A. Frost, Gavin Carothers,
+ Glenn McDonald, Guus Schreiber, Henri Bergius, Jose María Alvarez Rodríguez,
+ Ivan Herman, Jack Moffitt, Josh Mandel, KANZAKI Masahide, Kingsley Idehen,
+ Kuno Woudt, Larry Garfield, Mark Baker, Mark MacGillivray, Marko Rodriguez,
+ Melvin Carvalho, Nathan Rixham, Olivier Grisel, Paolo Ciccarese, Pat Hayes,
+ Patrick Logan, Paul Kuykendall, Pelle Braendgaard, Peter Williams, Pierre-Antoine Champin,
+ Richard Cyganiak, Roy T. Fielding, Sandro Hawke, Srecko Joksimovic,
+ Stephane Fellah, Steve Harris, Ted Thibodeau Jr., Thomas Steiner, Tim Bray,
+ Tom Morris, Tristan King, Sergio Fernández, Werner Wilms, and William Waites.</p>
+</section>
+
+
+
+<section rel="bibo:chapter" resource="#references" typeof="bibo:Chapter" class="appendix" id="references"><!--OddPage--><h2><span class="secno">G. </span>References</h2><section rel="bibo:chapter" resource="#normative-references" typeof="bibo:Chapter" id="normative-references"><h3><span class="secno">G.1 </span>Normative references</h3><dl about="" class="bibliography"><dt id="bib-BCP47">[BCP47]</dt><dd rel="dcterms:requires">A. Phillips; M. Davis. <a href="http://tools.ietf.org/html/bcp47"><cite>Tags for Identifying Languages</cite></a>. September 2009. IETF Best Current Practice. URL: <a href="http://tools.ietf.org/html/bcp47">http://tools.ietf.org/html/bcp47</a>
+</dd><dt id="bib-RDF-CONCEPTS">[RDF-CONCEPTS]</dt><dd rel="dcterms:requires">Richard Cyganiak, David Wood, Editors. <cite><a href="http://www.w3.org/TR/2013/WD-rdf11-concepts-20130115/">RDF 1.1 Concepts and Abstract Syntax.</a></cite> 15 January 2013. W3C Working Draft (work in progress). URL: <a href="http://www.w3.org/TR/2013/WD-rdf11-concepts-20130115/">http://www.w3.org/TR/2013/WD-rdf11-concepts-20130115/</a>
+</dd><dt id="bib-RFC2119">[RFC2119]</dt><dd rel="dcterms:requires">S. Bradner. <a href="http://www.ietf.org/rfc/rfc2119.txt"><cite>Key words for use in RFCs to Indicate Requirement Levels.</cite></a> March 1997. Internet RFC 2119. URL: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a>
+</dd><dt id="bib-RFC3987">[RFC3987]</dt><dd rel="dcterms:requires">M. Dürst; M. Suignard. <a href="http://www.ietf.org/rfc/rfc3987.txt"><cite>Internationalized Resource Identifiers (IRIs)</cite></a>. January 2005. RFC 3987. URL: <a href="http://www.ietf.org/rfc/rfc3987.txt">http://www.ietf.org/rfc/rfc3987.txt</a>
+</dd><dt id="bib-RFC4627">[RFC4627]</dt><dd rel="dcterms:requires">D. Crockford. <a href="http://www.ietf.org/rfc/rfc4627.txt"><cite>The application/json Media Type for JavaScript Object Notation (JSON)</cite></a>. July 2006. RFC 4627. URL: <a href="http://www.ietf.org/rfc/rfc4627.txt">http://www.ietf.org/rfc/rfc4627.txt</a>
+</dd><dt id="bib-RFC5988">[RFC5988]</dt><dd rel="dcterms:requires">M. Nottingham, Editor. <cite><a href="http://tools.ietf.org/rfc/rfc5988">Web Linking</a>.</cite> October 2010. Internet RFC 5988. URL: <a href="http://tools.ietf.org/rfc/rfc5988.txt">http://tools.ietf.org/rfc/rfc5988.txt</a>
+</dd></dl></section><section rel="bibo:chapter" resource="#informative-references" typeof="bibo:Chapter" id="informative-references"><h3><span class="secno">G.2 </span>Informative references</h3><dl about="" class="bibliography"><dt id="bib-HTTP11">[HTTP11]</dt><dd rel="dcterms:references">R. Fielding et al. <a href="http://www.ietf.org/rfc/rfc2616.txt"><cite>Hypertext Transfer Protocol - HTTP/1.1</cite></a>. June 1999. RFC 2616. URL: <a href="http://www.ietf.org/rfc/rfc2616.txt">http://www.ietf.org/rfc/rfc2616.txt</a>
+</dd><dt id="bib-JSON-LD-API">[JSON-LD-API]</dt><dd rel="dcterms:references">Markus Lanthaler, Gregg Kellogg, Manu Sporny, Editors. <cite><a href="http://json-ld.org/spec/latest/json-ld-api/">JSON-LD 1.0 Processing Algorithms and API</a>.</cite> W3C Editor's Draft (work in progress). URL: <a href="http://json-ld.org/spec/latest/json-ld-api/">http://json-ld.org/spec/latest/json-ld-api/</a>
+</dd><dt id="bib-MICRODATA">[MICRODATA]</dt><dd rel="dcterms:references">Ian Hickson, Editor. <cite><a href="http://www.w3.org/TR/2012/WD-microdata-20120329/">HTML Microdata</a>.</cite> 29 March 2012. W3C Working Draft (work in progress). URL: <a href="http://www.w3.org/TR/2012/WD-microdata-20120329/">http://www.w3.org/TR/2012/WD-microdata-20120329/</a>
+</dd><dt id="bib-MICROFORMATS">[MICROFORMATS]</dt><dd rel="dcterms:references"><a href="http://microformats.org"><cite>Microformats</cite></a>. URL: <a href="http://microformats.org">http://microformats.org</a>
+</dd><dt id="bib-PROFILE-LINK">[PROFILE-LINK]</dt><dd rel="dcterms:references">Erik Wilde. <cite><a href="http://tools.ietf.org/html/draft-wilde-profile-link">The 'profile' Link Relation Type</a>.</cite> 17 October 2012. IETF Internet Draft (work in progress). URL: <a href="http://tools.ietf.org/html/draft-wilde-profile-link">http://tools.ietf.org/html/draft-wilde-profile-link</a>
+</dd><dt id="bib-RDF-SCHEMA">[RDF-SCHEMA]</dt><dd rel="dcterms:references">Dan Brickley; Ramanathan V. Guha. <a href="http://www.w3.org/TR/2004/REC-rdf-schema-20040210"><cite>RDF Vocabulary Description Language 1.0: RDF Schema</cite></a>. 10 February 2004. W3C Recommendation. URL: <a href="http://www.w3.org/TR/2004/REC-rdf-schema-20040210">http://www.w3.org/TR/2004/REC-rdf-schema-20040210</a>
+</dd><dt id="bib-RDFA-CORE">[RDFA-CORE]</dt><dd rel="dcterms:references">Shane McCarron et al. <a href="http://www.w3.org/TR/2012/REC-rdfa-core-20120607/"><cite>RDFa Core 1.1: Syntax and processing rules for embedding RDF through attributes</cite></a>. 7 June 2012. W3C Recommendation. URL: <a href="http://www.w3.org/TR/2012/REC-rdfa-core-20120607/">http://www.w3.org/TR/2012/REC-rdfa-core-20120607/</a>
+</dd><dt id="bib-TURTLE-TR">[TURTLE-TR]</dt><dd rel="dcterms:references">Eric Prud'hommeaux, Gavin Carothers, Editors. <cite><a href="http://www.w3.org/TR/2011/WD-turtle-20110809/">Turtle: Terse RDF Triple Language.</a></cite> 09 August 2011. W3C Working Draft (work in progress). URL: <a href="http://www.w3.org/TR/2011/WD-turtle-20110809/">http://www.w3.org/TR/2011/WD-turtle-20110809/</a>
+</dd></dl></section></section></body></html>