Web Resource Identity

Paul Prescod paul at prescod.net
Fri May 28 19:58:31 BST 1999

Walter Underwood wrote:
> Don't forget content negotiation. 

Those are different manifestations of the same resource. I think that we
eventually need to be able to address manifestations so that I could make
a URL to the MS Word version of a document or to the PDF version
explicitly...or even to the document with a particular CSS stylesheet

> Then there are dynamic pages--what is "identity" for a weather
> station? The page is in some sense "the same page", but the
> content depends on the temperature.

Human beings decide identity. If we think of the weather page as a
"thing", then we should assign it a Unique ID so that we can refer to it.

Anyhow, if the two manifestations were retrieved with the same URL then
the answer is already in the W3C specs: they are the same object. It is
the multiple URL->one resource case that the Web does not currently seem
to support.

> Finally, some systems ignore case in file names, and relative
> URLs are resolved according to the URL you used in the GET,
> so we see:
>    http://www.corp.com/dir/index.html
>    http://www.corp.com/DIR/index.html
> ...
> with combinatorial explosions on longer URLs. And a nightmare
> for robots and caching proxies.

Globally unique identifiers would help with that. Dynamic content will
always be a nightmare but XML node inclusion could help by separating out
the dynamic parts from the static parts.

 Paul Prescod  - ISOGEN Consulting Engineer speaking for only himself

Alabama's constitution is 100 years old, 300 pages long and has more than
600 amendments. Highlights include "Amendment 393: Amendment of Amendment
No.  351", "Validation of Laws Regulating Court Costs in Randolph County",
"Miscegenation laws", "Bingo Games in Russell County", "Suppression
of dueling".  - http://www.legislature.state.al.us/ALISHome.html

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