- From: Daniel R. Tobias <dan@tobias.name>
- Date: Wed, 17 Sep 2003 11:13:22 -0400
- To: uri@w3.org
On 17 Sep 2003 at 12:30, Patrick.Stickler@nokia.com wrote: > The HTTP protocol seems only to be telling you how to obtain > representations of whatever is denoted by the URI, not how to > obtain the actual semantics/denotation of the URI. Well, it's a URL (Uniform Resource Locator) rather than a URN (Uniform Resource Name), after all. Its intent has always been to tell you how to obtain something rather than to define exactly what it is. Webmasters find this out to their dismay when links in their site to relevant resources suddenly turn into links to porn sites because a domain name expired and was picked up by an adult site operator (this has happened with links in my site several times). I'd say that, by definition, the URI http://foo.example/some/junk/ denotes whatever can be retrieved by the HTTP protocol using this host and path. It might lead to a Web page, a raw directory listing, a redirect to another URI, a 404 Not Found error, or a domain lookup error, and it may change to something else tomorrow, but the URI refers to the abstract contents of the particular address. Similarly, a postal address like "3 Maple Street" refers to a postal delivery location, and perhaps to whatever building happens to be there now, but doesn't tell you anything about who is actually at that address, which is subject to constant change. The building there might even get torn down and replaced with something else, so maybe there was a residence at 3 Maple Street 10 years ago but an office building today. The city might also decide to rename or renumber their streets and addresses so that next year "3 Maple Street" refers to a location across town from where it did this year. These sorts of addresses can be used to designate where some resource can be found at present, but have no definitional quality to permanently and unambiguously define what the resource is. Some other scheme, otherwise defined, is needed if you need such a designation for permanent reference to an entity. This is not to say that the manager of a particular group of URIs, within a scheme that is a locator rather than a permanent name, can't announce particular semantics for addresses, like to say that http://foo.example/newsletter/latest.html will always have the latest issue of their newsletter, while http://foo.example/newsletter/2003- 09-11.html has the September 11, 2003 issue, but that's not part of the definition of the scheme and is not guaranteed to work permanently; the manager could change his/her mind about the naming structure, or be replaced by a new manager who rearranges everything, or the site owner could go out of business altogether. -- == Dan == Dan's Mail Format Site: http://mailformat.dan.info/ Dan's Web Tips: http://webtips.dan.info/ Dan's Domain Site: http://domains.dan.info/
Received on Wednesday, 17 September 2003 12:11:13 UTC