W3C home > Mailing lists > Public > uri@w3.org > March 2004

Re: FW: fragment prose proposal

From: Graham Klyne <GK@ninebynine.org>
Date: Sun, 29 Feb 2004 15:45:32 +0000
Message-Id: <>
To: tony@tonyhammond.net, uri@w3.org

At 18:32 28/02/04 +0000, Tony Hammond wrote:

>Hi Graham:
>>So even if you assert that the resource identified by a given URI has no
>>retrievable representation, I think it's fairly trivial to construct an
>>environment in which there *is* a retrievable representation for what that
>>URI denotes (unless its denotation is so obscure as to defy having any
>>reasonable representation, but that doesn't seem very useful to me).
>You guys are gonna have to educate me. If (as you seem to be asserting) 
>one can plug in any old retrieval mechanism for a self-declared 
>non-dereferenceable scheme (such as INFO), then presumably one could do 
>the same wrt any other scheme - e.g. construct an FTP retrieval mechanism 
>against an HTTP URI, or a Handle retrieval mechanism, or whatever. Am I 
>missing something here or don't things begin to fall apart if just any ad 
>hoc retrieval mechanisms are recognized client side? What is the point 
>then of a URI scheme if clients can override any given protocol and do as 
>they want? Isn't that just a smidgen close to anarchy?

I have little to add to Roy's response.

Just that it's not anarchy because the given scheme, when based on a 
network protocol, still indicates the definitive way to access the 
resource.  If one uses another protocol, then it should return the same or 
compatible information, or else it's lying (or outside the Web)

In the case of my example, it means that *any* retrieval mechanism 
constructed must return something compatible with the defined referent of 
the (say, info:) URI, so it's not quite open season.

>BTW - Isn't it marvelous that absolutlely /no/ browsers can recognize a 
>generic URI string, even now some ten years after? :~) All of 'em just 
>manage to scrape through with a few hard-wired schemes (the 'GETables') 
>which they deign to recognize. Quite surprised that even now the 
>standards-compliant-wannabe clients simply cannot recognize a URI string 
>in context. What does that say about the state of the Web?

Well, to adopt a slightly different take to Roy's, I'd say that a browser 
is specifically concerned with retrieval (and rendering) of resource 
representations, so it's maybe forgivable if it doesn't grok schemes that 
it doesn't know how to retrieve.  (Though one might argue that any browser 
should be able to send a generic URI to a proxy, which might grok more.)


Graham Klyne
For email:
Received on Monday, 1 March 2004 11:16:51 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:25:07 UTC