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Re: Enforce reloading of page when using the back-button

From: Jeff Sinclair <jeffs@kestral.com.au>
Date: Fri, 17 Mar 2000 12:03:54
Message-Id: <>
To: www-talk@w3.org
According to the HTTP/1.0 spec :

  "HTTP status codes are extensible, but the above codes are the only
   ones generally recognized in current practice. HTTP applications are
   not required to understand the meaning of all registered status
   codes, though such understanding is obviously desirable. However,
   applications must understand the class of any status code, as
   indicated by the first digit, and treat any unrecognized response as
   being equivalent to the x00 status code of that class, with the
   exception that an unrecognized response must not be cached. For
   example, if an unrecognized status code of 431 is received by the
   client, it can safely assume that there was something wrong with its
   request and treat the response as if it had received a 400 status
   code. In such cases, user agents should present to the user the
   entity returned with the response, since that entity is likely to
   include human-readable information which will explain the unusual

This means that is you return a "220 O.K." the browser must treat it like a 
200 O.K. except for the fact that it must not cache the page. 

We also had to add <META HTTP-EQUIV="Pragma" CONTENT="no-cache">  to the pages 
( which had previously on it's own had not worked )

We tested this and it works to break the back button for IE4, IE5.1, 
Netscape 3.04 And 4.04. All of the pages made a new request to the server.

Unfortunately IE 3.01 on NT 3.5 still cached the pages.

Jeff Sinclair
Kestral Computing
Received on Thursday, 16 March 2000 22:56:47 UTC

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