XML Base (was Re: Ontology modules and namespaces)

Hi Alan

you seem to have forgotten yourself, or at least that bit of yourself 
that read the OWL 2 documents.

Alan Ruttenberg wrote:
> As far as any of the semantic web technologies go xml:base *does not
> exist*. The specs know *nothing* about it. Nor should they.
>
>   
I read:
http://www.w3.org/TR/2009/REC-owl2-xml-serialization-20091027/#IRIs
/[[
MUST/ be resolved against the respective /base IRI/ as specified in the 
XML Base specification [XML Base 
<http://www.w3.org/TR/2009/REC-owl2-xml-serialization-20091027/#ref-xml-base>]. 

]]

I read
http://www.w3.org/TR/2009/REC-owl2-primer-20091027/#Ontology_Management
and see the second set of examples using xml:base in both the RDF/XML 
and the OWL/XML

The automated converter for the OWL2 tests appears to add xml:base for 
both RDF/XML and OWL/XML formats,
e.g. see
http://owl.semanticweb.org/page/Qualified-cardinality-restricted-int

The OWL1 test cases all have explicit xml:base


What is the role of an xml:base, well that is explained in RFC 3986, 
section 5.1.1. This explicitly takes precedence over the retrieval URI, 
when doing base conversions.

In particular, the function of TopBraid Composer which adds an 
appropriate xml:base declaration to a file to allow a copy to be stored 
locally, and for relative URI computations to be made correctly seems to 
be the primary intended purpose.

(Of course, there is also a normative dependency from OWL2 to xml:base 
via RDF/XML Syntax)

Jeremy

Received on Tuesday, 10 November 2009 22:31:23 UTC