The usability of RDF is heavily dependent on the portability of the
data defined in the RDF models and its ability to be interchanged
with other data. Unfortunately, recording the RDF data in a
graph?the default RDF documentation format?is not the
most efficient means of storing or retrieving this data. Instead,
transporting RDF data, a process known as
usually occurs with RDF/XML.
Originally, the RDF model and the RDF/XML syntax were incorporated
into one document, the Resource Description
Framework (RDF) Model and Syntax Specification. However, when the
document was updated, the RDF model was separated from the document
detailing the RDF/XML syntax. Chapter 2 covered
the RDF abstract model, graph, and semantics; this chapter provides a
general introduction to the RDF/XML model and syntax (RDF M&S).
The original RDF M&S
Specification can be found at http://www.w3.org/TR/REC-rdf-syntax/. The
updated RDF/XML Syntax Specification (revised) can be found at
Some RDF-specific aspects of RDF/XML
at first make it seem overly complex when compared to non-RDF XML.
However, keep in mind that RDF/XML is nothing more than well-formed
XML, with an overlay of additional constraints that allow for easier
interchange, collection, and mergence of data from multiple models.
In most implementations, RDF/XML is parsable with straight XML
technology and can be manipulated manually if you so choose.
It's only when the interchangeability of the data is
important and the data can be represented only by more complex data
structures and relationships that the more formalized elements of RDF
become necessary. And in those circumstances, you'll
be glad that you have the extra capability.
All examples listed in the chapter are
validated using the W3C's RDF Validator, located at