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Re: A.10.1

From: Nir Dagan <nir@nirdagan.com>
Date: Fri, 29 Jan 1999 01:56:01 GMT
Message-Id: <199901281643.RAA18143@sahara.upf.es>
To: w3c-wai-gl@w3.org
With all due respect, there is no such thing as 
"instant rediction" or "timed response".

The optimal way to redirect the user to a new page
when a URL is moved permanently is by returning 
the status code 301 as per HTTP/1.1 (some older servers 
like CERN's can't do that but can give a 302 status code which is 
almost as good)

Whether this is instant or not is up to the user agent.
For example the W3C validator recognizes the HTTP status 
codes 301 and 302 but informes the user of the new location 
rather than validating instantly the document in the new location.

I would recommend using the appropriate redirect HTTP status,
and if this is impossible, just to place a page with a normal link 
to the new URL, indicating that this technique is suboptimal as 
link checker programs and indexing robots are less likely to update 
their records timely if at all. For the sake of completeness I would mention
the the META refresh thing is non-standard (without a disscussion)
and that it is not supported by many agents.

Regards,

Nir Dagan
Assistant Professor of Economics
Universidad Pompeu Fabra
Ramon Trias Fargas 25
08005 Barcelona
Spain

http://www.nirdagan.com
mailto:nir@nirdagan.com

"There is nothing quite so practical as a good theory." 
-- A. Einstein
Received on Thursday, 28 January 1999 11:54:03 GMT

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