Houghton,Andrew wrote:
> RFC 3986 (URI generic syntax) says that "http:" is a URI scheme not a
> protocol.  Just because it says "http" people make all kinds of 
> assumptions about type of use, persistence, resolvability, etc.

And RFC 2616 (Hypertext transfer protocol) says:

"The HTTP protocol is a request/response protocol. A client sends a 
request to the server in the form of a request method, URI, and protocol 
version, followed by a MIME-like message containing request modifiers, 
client information, and possible body content over a connection with a 

So what you are saying is that it's ok to use the URI for the hypertext 
transfer protocol in a way that ignores RFC 2616. I'm just not sure how 
functional that is, in the grand scheme of things. And when you say:

> The "Cool URIs for the Semantic Web" document describes how an HTTP protocol
> implementation (of RFC 2616) should respond to a dereference of an HTTP URI.

I think you are deliberating distorting the intent of the Cool URIs 
document. You seem to read it that *given* an http uri, here is how the 
protocol should respond. But in fact the Cool URIs document asks the 
question "So the question is, what URIs should we use in RDF?" and 
responds that one should use http URIs for the reason that:

"Given only a URI, machines and people should be able to retrieve a 
description about the resource identified by the URI from the Web. Such 
a look-up mechanism is important to establish shared understanding of 
what a URI identifies. Machines should get RDF data and humans should 
get a readable representation, such as HTML. The standard Web transfer 
protocol, HTTP, should be used."

So it doesn't just say how to respond to an http URI; it says to use 
http URIs *because* there is a useful possible response. That's a very 
different statement. It is signficant that (as Mike pointed out, perhaps 
inadvertently) no one is using mailto: or ftp: as identifiers. That's 
not a coincidence.


Karen Coyle / Digital Library Consultant
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