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FW: Comments on Content Transformation Guidelines? (LC-2065)

From: Sullivan, Bryan <BS3131@att.com>
Date: Mon, 29 Sep 2008 23:08:33 -0700
Message-ID: <8080D5B5C113E940BA8A461A91BFFFCD0B9EA6BD@BD01MSXMB015.US.Cingular.Net>
To: "public-bpwg-ct" <public-bpwg-ct@w3.org>
Hi all,

Forwarding this email since I did not see it in the agenda for
tomorrow's call (which I won't be attending, but feel free to consider
this response).


Best regards,

Bryan Sullivan | AT&T


From: public-bpwg-comments-request@w3.org
[mailto:public-bpwg-comments-request@w3.org] On Behalf Of Sullivan,
Sent: Tuesday, September 23, 2008 12:17 AM
To: Dennis Bournique
Cc: public-bpwg-comments@w3.org
Subject: Re: Comments on Content Transformation Guidelines? (LC-2065)


Hi Dennis,

I took the action to propose some text for your comments. I had similar
input way back at the start of the CT Guidelines work, so I will
resurrect some of it here. The statements are terse by design. They can
be elaborated on but the essence of the requirement is what should be
agreed upon first, then the requirement level. 

(this is a new section)

4.4 User Control 

4.4.1 Original Representation Availability

A CT proxy SHALL provide availability of the original representation for
a CP response.

4.4.2 Selecting Content Representation Dynamically

A CT proxy SHALL support user switching between the available
representations for a CP response, including the original representation
and transformed representations.

A CT proxy SHALL provide content in the chosen representation until the
user chooses another representation.

4.4.3 Selecting Content Representation as a Preference

A CT proxy MAY enable the user to select a preference for a content
representation from among those available through the proxy.

A CT proxy that offers user-selection of content representations SHOULD
be capable of user selection of such preferences for specific domains
and globally for all domains.

Best regards,

Bryan Sullivan | AT&T

From: Dennis Bournique <db@wapreview.com
d.yahoo.com%253E> >
Date: Thu, 28 Aug 2008 13:23:10 -0700 (PDT)
To: public-bpwg-comments@w3.org
Message-ID: <368635.28409.qm@web81606.mail.mud.yahoo.com> 

Thanks for the response Jo.

I looked at the sections of the Guidelines that you referred to and the
strongest statement regarding user opt-out is in the Introduction which
is non-normative.

> 1.4 Summary of Requirements


>       5 The Content Transformation proxy needs to be able to interact
>with the user:

>           1. to allow the user to disable its features;

>           2. to alert the user to the fact that it has transformed 

> content and to allow access to an untransformed representation of the 

> content.


In the normative sections that you refer to:

Section 4.1.5 is about not altering headers and does not address opt-out

Section refers to allowing the user to request a restructured
experience - which I take to mean allowing the user to opt-in to
transcoding even if the server provides a mobile specific version of the
resource. I don't have any issues with that. Users should certainly be
able to opt-in to transcoding of any content.  

What seems to be missing is a mandatory requirement that users be able
to opt-out of content transformation for any page or all pages. 

The closest thing is in

> Alteration of Response


> If a proxy alters the response then:


>     1. ...

>     2. ...

>     3. It should indicate to the user that the content has been 

> transformed for mobile presentation and provide an option to view the 

> original, unmodified content.

I'm concerned with the use of "should" rather than "must".  To me,
"Should" implies that providing opt-out is recommend rather than

In terms of not breaking existing sites and servers, opt-out is what is
important. If the user believes that a transcoded resource is
unsatisfactory, they "must" be able to request the original
un-transformed resource. I'd think opt-out is too important to be a

Regarding session management, If the user requests an un-transcoded
experience there is no need to maintain the current session.  A simple
link to the original resource should suffice.  This is what several
existing off-portal transcoders do including Skweezer, Mowser and Google
GWT.  The user may have to re-login, etc., but I don't see any practical
way to maintain the session which is likely to based on cookies held by
the proxy. Opting-out takes the proxy out of the picture so session loss
is inevitable.
Received on Tuesday, 30 September 2008 06:09:18 UTC

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