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Re: [Fwd: Re: Issue-57]

From: Yves Lafon <ylafon@w3.org>
Date: Fri, 1 Jul 2011 12:13:01 -0400 (EDT)
To: David Booth <david@dbooth.org>
cc: Ian Davis <lists@iandavis.com>, Tim Berners-Lee <timbl@w3.org>, "www-tag@w3.org List" <www-tag@w3.org>
Message-ID: <alpine.DEB.1.10.1107011209050.21932@wnl.j3.bet>
On Fri, 1 Jul 2011, David Booth wrote:

>>> would help us avoid the IR/non-IR rat hole in that discussion.  What do
>>> you think?
>> There are quite a few situations where the representations of a
>> resource do not share its properties. For example, the generator of a
>> resource might be OpenOffice, but the generator of its representation
>> could be Apache. And of course intermediaries could be modifying the
>> representations along the way without permission by publisher or
>> consumer. For example, many mobile ISPs transcode images to save
>> bandwidth and even inject javascript into pages to provide tooltips on
>> those images saying "click image to improve quality". This risks
>> confusion when the representations include license information as the
>> end user could easily assume wrongly that the license covers the
>> injected script.
> True.  When we say that the license applies to "all http
> representations" that should be understood to mean "all *authorized*
> http representations", since the publisher cannot be held responsible
> for changes made to the representation by intermediaries during
> transport.

See http://tools.ietf.org/html/rfc2616#section-14.46
It defines extra information sent via a "Warning" header
    214 Transformation applied
      MUST be added by an intermediate cache or proxy if it applies any
      transformation changing the content-coding (as specified in the
      Content-Encoding header) or media-type (as specified in the
      Content-Type header) of the response, or the entity-body of the
      response, unless this Warning code already appears in the response.
So, in theory, the receiver should know when the representation has been 
modified in transit.

Baroula que barouleras, au tiƩu toujou t'entourneras.

Received on Friday, 1 July 2011 16:13:03 UTC

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