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Use of metadata in URIs

From: Larry Masinter <LMM@acm.org>
Date: Sun, 28 Sep 2003 09:58:11 -0700
To: www-tag@w3.org
Message-id: <000d01c385e1$b36ae9d0$6401a8c0@MasinterT40>

I think the problem is that 
http://www.w3.org/2001/tag/doc/metaDataInURI-31.html
has looked at the problem from the wrong perspective.

"...outside of their own authority (i.e. observers)..."

I don't think the web architecture is (or can  be)
clear about the notion of "authority". It's some terminology
that has crept into many of the discussions about URIs
and their meaning, and I think it's misplaced.

The only URI scheme registered that acknowledges that there
might be an "authority" that "assigns" URIs is the
"urn:" scheme.  Most other URI schemes give an
operational definition -- "http:" about using the
HTTP, "ftp:" about using the file transfer protocol,
"mailto:" about sending mail.

I think what the finding is trying to get at could
be better stated as follows:

There may be policies and processes involved in creating
or resources and other communication endpoints that
can be reached using particular URIs, but an agent
looking at or trying to interpret those URIs should
not make any assumptions beyond those that are actually
defined by the URI scheme definition itself.

Since the HTTP protocol doesn't require that
URIs ending in ".html" are really text/html,
or that URIs not ending in ".html" are not,
then an agent looking at a http URI shouldn't
try to infer its type from the URI ending.

(On the other hand, the definition of the "file:" URI
scheme probably _should_ assign such meanings....)

Larry
-- 
http://larry.masinter.net
Received on Sunday, 28 September 2003 12:58:19 GMT

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