LC Responses/JO1

[Draft Response for LC Comment 63:] JO1

Dear Jacco,

Thank you for your message


on the OWL 2 Web Ontology Language last call drafts.

The Working Group acknowledges that the recent last call document set confused some readers, particularly with respect to the overall OWL 2 environment and the various syntaxes for OWL 2. At its last face-to-face meeting the Working Group has, therefore, added a new document to the OWL 2 suite, entitled "Document Overview". The document has not yet been published, but an editor's draft is publicly available at:

The Document Overview document describes the status of the various syntaxes for OWL 2 and clearly states that RDF/XML is the primary syntax for the exchange of OWL 2 ontologies. This status is reiterated in the Conformance document. The Document Overview document states that the XML syntax need not be supported by OWL 2 tools.

There are other parts of the OWL 2 recommendation that are optional as well. There can be OWL 2 tools that only implement OWL 2 RL, for example.

The reason for a normative and recommendation track status for the OWL 2 XML syntax is to say that OWL 2 tools that use an XML schema specified syntax for the exchange of ontology documents *should* use the XML schema provided in the OWL 2 recommendation. Making the XML syntax a working group note would not provide this sort of guidance.

To make the status of the XML syntax clearer, the introduction to the XML Schema document has been changed to:

This document defines the XML syntax for OWL 2, an alternative exchange syntax for OWL 2 designed for use by XML tools (e.g., tools using, for example, XQuery [XQuery]). Although this XML syntax is designed as an exchange syntax for OWL 2, RDF/XML remains the primary exchange syntax for OWL---use of this syntax by OWL 2 tools is optional.

The XML syntax mirrors the structural specification of OWL 2 [OWL 2 Specification] and is defined by means of an XML schema [XML Schema], which is available as part of this document. The XML schema has been obtained by a straightforward translation of the structural specification of the OWL 2 Specification [OWL 2 Specification] in the following way:

The Working Group plans on making the examples in the OWL 2 Structural Specification and Functional Syntax document available in other syntaxes, even though that document only defines one syntax. The Working group does not intend to make changes to the XML Serialization document in response to your message.

We hope that the new document and other upcoming changes address your concerns.

Please acknowledge receipt of this email to <> (replying to this email should suffice). In your acknowledgment please let us know whether or not you are satisfied with the working group's response to your comment.

Regards, Peter F. Patel-Schneider on behalf of the W3C OWL Working Group

Last modified on 16 March 2009, at 21:26