- From: Henrik Frystyk Nielsen <frystyk@microsoft.com>
- Date: Mon, 19 Jun 2000 15:22:09 -0700
- To: "David Carlisle" <david@dcarlisle.demon.co.uk>
- Cc: <XML-uri@w3.org>
> > What you are proposing is another "case A" [3] scenario that several > > people have pointed out as flawed. > > I am not proposing it, it is a W3C recommendation. > It is not `case A' (the same namespace name resolving two different > resources) it is the `harmless' `case B' (two different namespace > names, differing by case, resolving to the same resource). I am sorry but this is simply not what you have been saying in other mails. Take for example your statment in [1] where you say If I need to define two namespaces to use in some document then I can use http://www.dcarlisle.demon.co.uk and http://WWW.DCARLISLE.DEMON.CO.UK it is _not_ at the liberty of some consumer of the document to decide that it understands DNS names and URI scheme sufficiently that it can decide the namespaces are equivalent. If I'd wanted to use the same namespace in both cases, I would have done so. These *cannot* be two different namespaces with different semantics - this is *exactly* a case A - what at one level (the naming authority) is identical, you want to be different at a higher level. Yes, you have to make a choice - if you want to use DNS names and the like as provided by HTTP URIs you have to follow the semantics. What is OK to say is that a namespace parser doesn't have to KNOW that these are identical but you when writing the document cannot assign different semantics to the two names. If you want to use a URI where there is absolutely no discussion about whether parts of it is case-sensitive or not, use a GUID. > Of course even the `case A' situation is not considered flawed > by those people arguing for the literal interpretation, which has > always been the majority view of any list that has ever discussed > this, as far as I can tell. Two instances of the same relative URI > reference may resolve to different resources, depending on context, > and namespace names are defined to be URI references, so aquire > the same feature. W3C can change this if they like, but it is not > flawed. If you want that then use a file URI or a news URI. You pick the namespace you want with the semantics you want - URIs allow you to do that - but you simply can't build a Web out of file: identifiers. So unless you can prove that it is possible to build a decentralized Web out of file: identifiers (without saying that everybody should move into AFS) then I can't see that you have a case at all. Henrik
Received on Monday, 19 June 2000 18:22:47 UTC