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RE: Use of metadata in URIs

From: Larry Masinter <LMM@acm.org>
Date: Mon, 29 Sep 2003 20:46:05 -0700
To: "'Williams, Stuart'" <skw@hp.com>
Cc: www-tag@w3.org
Message-id: <000301c38705$605fc060$6401a8c0@MasinterT40>

(trying to keep this short)

> I was actually trying to explore from two perspectives... that of an
> assignment authority (and the infrastructure under their control, eg.
origin
> servers - and maybe CDNs); and that of 'observers' of URI assigned
outside
> of their own authority. It seems to me that the 'freedoms' to read
something
> into a URI are different from each perspective.

The finding says it is intended to address two related questions:

1. What, if anything, can be inferred from a URI used to identify a
resource?
2. What information about a resource can or should be embedded in a URI
used
   to identify that resource?

Neither of these questions seems to be posed from the point of
view of an 'authority' who might 'assign' a URI. URIs are used
in communication. There is the agent (person or software) that
utters (publishes, sends) the URI, and there is the agent 
(person or software) that receives and interprets the URI.

In some cases, there might also be some process or procedure
involving some agents that might cause a URI to be associated
with some resource, e.g., a webmaster at a web site configuring
a web server and a user of that site storing some file in
a directory that the configuration points to. But the intent
and roles of these agents ('authorities', if you like) aren't
really involved in the conversation about 'what, if anything,
can be inferred'.

When I tell you I have a comment about
 http://www.w3.org/2001/tag/doc/metaDataInURI-31.html,
our mutual understanding of the meaning of that URI doesn't
depend on whoever has "control" or "authority" over "www.w3.org",
except for our mutual belief that when we poke that URI
we will get the same reaction. It's an operational understanding.
Even when an authority does have something to say about a 'http'
URI, the authority (should) make its will known by doing
something operational.


(from RFC 2396)
>   "3.2. Authority Component
> 
>      Many URI schemes include a top hierarchical element for a naming
>      authority, such that the namespace defined by the remainder of
the
>      URI is governed by that authority. This authority component is
>      typically defined by an Internet-based server or a
scheme-specific
>      registry of naming authorities."

Perhaps it should be clearer, but the goal of this wording was to define
the generic syntax, and to allow the generic syntax to be used in a
wide variety of schemes. RFC 2396 never mandates that schemes use
the generic syntax, it just makes it available. So I don't think the
generic syntax should ever be taken as _definitional_ for the meaning
of URIs. Every scheme that uses the generic syntax must still say,
operationally, how the components are combined to create semantics.
Received on Monday, 29 September 2003 23:46:35 GMT

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