- From: Jonathan Borden <jborden@mediaone.net>
- Date: Fri, 15 Sep 2000 19:52:02 -0400
- To: "Dan Connolly" <connolly@w3.org>
- Cc: <www-rdf-interest@w3.org>
Dan Connolly wrote: > Jonathan Borden wrote: > > > > What specification constrains the contents of a namespace? > > If you mean "what specification constraints the content > you get back when dereferencing a namepace name" then > the answer is the same as the answer to > "what spec constrains the content > you get back when you dereference an HTML href?" > There is no spec for what you get back in the general case. No, I mean: what specification constrains the local-names() which can be used as part of a QName given a particular namespace-uri(). An RDF Schema provides a mechanism to define 'members' of a namespace, but it does not contain a mechanism to *exclude* members of a namespace, nor does it provide a mechanism to state that a particular Schema, as might be presented in a specification, defines the only members of a namespace. A DTD, and XML Schema *could* constrain which elements might be children of <rdf:RDF> for example, but where does it say that I can't define e.g. <rdf:foo> to be used outside of an <rdf:RDF> root? > > > > It is logical > > that the owner of a namespace (whatever that means) may restrict the ability > > of others to add elements to the namespace but where is this precisely > > specified? > > That ends with a question mark but parses as a declarative > sentence. Help? Do you mean "is it logical ..."? I mean: "It is logical ... But where is this precisely specified?" > > Absolutely, it's logical for the issuer of a namespace > name, like any other URI, to say what that URI means, > and what it doesn't mean. > > W3C has stated both: > > The formal namespace name for the properties and > classes defined in this specification is > http://www.w3.org/1999/02/22-rdf-syntax-ns#. > ... > > [[[ > This is the RDF Schema for the RDF data model as described in > the Resource Description Framework (RDF) Model and > Syntax Specification http://www.w3.org/TR/REC-rdf-syntax > ]]] > These are statements. I've read them. Where does it say that I am not allowed to create the element "rdf:foo" and use it as I please (for example, outside of RDF). I understand that you don't like this activity, and I understand the arguments against allowing such actitivity. I just don't see a specification explicitly disallowing this activity. For example, one cannot say that a document containing "rdf:foo" is either not well-formed, nor not valid, nor not namespace compliant, etc. etc. > > > > Do you have the same issue with TimBL's rdf:for > > (http://www.w3.org/DesignIssues/Syntax)? > > No, TimBL doesn't say that rdf:for is short for > http://www.w3.org/1999/02/22-rdf-syntax-ns#for . > At least I hope he doesn't mean it that way. Good point. And don't get me wrong, what you are saying is the "Right Thing" and a best practice, but perhaps this needs to be codified in a standard. For example, a document which lists the members of a grammar. An XML Schema won't do, but perhaps 'allowable' usage of the grammar ought be specified as a set of XPath constraints/assertions ala Schematron. Jonathan Borden The Open Healthcare Group http://www.openhealth.org
Received on Friday, 15 September 2000 20:02:28 UTC