- From: Barclay, Daniel <daniel@fgm.com>
- Date: Mon, 31 Aug 2009 13:58:37 -0400
- To: <public-owl-comments@w3.org>
- Message-ID: <4A9C0F4D.4060601@fgm.com>
In the OWL 2 Web Ontology Language Structural Specification and Functional-Style Syntax draft at http://www.w3.org/TR/2009/CR-owl2-syntax-20090611/, section 2.4, IRIs, says: Ontologies and their elements are identified using Internationalized Resource Identifiers (IRIs) [RFC3987]; thus, OWL 2 extends OWL 1, which uses Uniform Resource Identifiers (URIs). Each IRI MUST be absolute. That wording probably should be adjusted so that readers don't accidentally assume that those IRIs must be absolute in the sense in which RFC 3986 uses the term (that is, not having fragment identifiers). That OWL specification is based on RFC 3987, and RFC 3987 is based on RFC 3986. Unfortunately, RFC 3968 doesn't use "absolute" in the normal sense (meaning not relative to something); it uses "absolute" to refer to not having a fragment identifier. Its section 4.3 (see http://tools.ietf.org/html/rfc3986#section-4.3) says: 4.3. Absolute URI Some protocol elements allow only the absolute form of a URI without a fragment identifier. For example, defining a base URI for later use by relative references calls for an absolute-URI syntax rule that does not allow a fragment. absolute-URI = scheme ":" hier-part [ "?" query ] ... Although that first sentence could be explained as first referring to URIs that are absolute in the usual sense and then only referring to the subset of those without fragments, it easily sounds like it's defining "absolute" to mean not having a fragment component. Regardless of that first sentence, the name of the absolute-URI production strongly implies that "absolute URI" refers to the strings matching that production. Given the lack of anything saying that the English phrase "absolute URI" does not in fact refer to what the absolute-URI grammar production generates, the only reasonable interpretation is that RFC 3986 defines "absolute URI" to refer to URIs without fragment components. Since allowing only non-fragment IRIs is _not_ what the OWL specification means to specify (right?), the OWL spec.'s text should also refer to not being relative or not being an IRI reference (or should refer to allowing fragment portions) to be clear. Daniel -- (Plain text sometimes corrupted to HTML "courtesy" of Microsoft Exchange.) [F]
Received on Monday, 31 August 2009 17:58:33 UTC