Reworked section on skolemization based on David Booth's feedback.
Related to #222.
--- a/spec/latest/json-ld/index.html Sat Jul 20 12:13:13 2013 +0200
+++ b/spec/latest/json-ld/index.html Sat Jul 20 15:29:12 2013 -0400
@@ -3169,7 +3169,7 @@
<tref href="http://www.w3.org/TR/rdf11-concepts/#dfn-concrete-rdf-syntax">concrete RDF syntax</tref>
as described in [[RDF11-CONCEPTS]]. Hence, a JSON-LD document is an
RDF document and a JSON document and correspondingly represents an
- instance of an extended RDF data model, namely
+ instance of an RDF data model, namely
<tref href="http://www.w3.org/TR/rdf11-concepts/#fn-generalized-rdf-dataset">generalized RDF Datasets</tref>.
The extensions to the RDF data model are:</p>
@@ -3193,21 +3193,44 @@
<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 directly
- interpreted as RDF. It is possible to work around this restriction, when
- interpreting JSON-LD as RDF, by transforming <tref title="blank node">blank nodes</tref>
- used as <tref title="property">properties</tref> to <tref title="IRI">IRIs</tref>,
+ interpreted as RDF as described in RDF 1.1 Concepts [[RDF11-CONCEPTS]].</p>
+
+ <p>For authors and developers working with
+ <tref title="blank node">blank nodes</tref> as
+ <tref title="property">properties</tref> when converting to RDF, there are
+ three potential approaches (in order of preference):</p>
+
+ <ol>
+ <li>If the author is not yet ready to commit to a stable IRI, the
+ property should be mapped to an IRI that is documented as unstable.</li>
+ <li>If the developer wishes to use
+ <tref title="blank node">blank nodes</tref> as
+ <tref title="property">properties</tref> and also wishes to interpret the
+ data as a
+ <tref href="http://www.w3.org/TR/rdf11-concepts/#fn-generalized-rdf-dataset">generalized RDF Dataset</tref>,
+ there is an option in the [[JSON-LD-API]] to do so.</li>
+ <li>If the author or developer wishes to use
+ <tref title="blank node">blank nodes</tref> as
+ <tref title="property">properties</tref> and wishes to interpret the data
+ as a non-generalized RDF Dataset, it is possible
+ to losslessly interpret JSON-LD as RDF by
+ transforming <tref title="blank node">blank nodes</tref> used as
+ <tref title="property">properties</tref> to <tref title="IRI">IRIs</tref>,
minting new "Skolem IRIs" as per
<cite><a href="http://www.w3.org/TR/rdf11-concepts/#section-skolemization">Replacing Blank Nodes with IRIs</a></cite>
- of [[RDF11-CONCEPTS]]. The normative algorithms for interpreting JSON-LD as RDF
- and serializing RDF as JSON-LD are specified in the
- JSON-LD Processing Algorithms and API specification [[JSON-LD-API]].</p>
+ of [[RDF11-CONCEPTS]].</li>
+ </ol>
+
+ <p>The normative algorithms for interpreting JSON-LD as RDF and serializing
+ RDF as JSON-LD are specified in the JSON-LD Processing Algorithms and API
+ specification [[JSON-LD-API]].</p>
<p>Even though JSON-LD serializes
<tref href="http://www.w3.org/TR/rdf11-concepts/#fn-generalized-rdf-dataset">generalized RDF Datasets</tref>, it can
also be used as a <tref href="http://www.w3.org/TR/rdf11-concepts/#dfn-rdf-source">RDF graph source</tref>.
In that case, a consumer MUST 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>
+ This allows servers to expose data in languages such as Turtle and JSON-LD
+ using content negotiation.</p>
<p class="note">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