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Re: ISSUE-187 - some thoughts on using javascript

From: Vinay Goel <vigoel@adobe.com>
Date: Fri, 9 Nov 2012 05:17:53 -0800
To: "Mike O'Neill" <michael.oneill@baycloud.com>, "'Roy T. Fielding'" <fielding@gbiv.com>, "'Shane Wiley'" <wileys@yahoo-inc.com>
CC: "'Walter van Holst'" <walter.van.holst@xs4all.nl>, "public-tracking@w3.org" <public-tracking@w3.org>
Message-ID: <CCC26C13.1D431%vigoel@adobe.com>
Hi Mike,

Why do you think this statement is true without any qualifiers "If users
delete all their cookies then they must mean they
want to return to DNT: 1, so that's fine."?

I don't think consumers would understand that DNT exceptions are stored in
cookies because DNT itself is stored within the UA.  Consumers would only
know that deleting their cookies means removing DNT exceptions if that's
told to the user when either deleting their cookies or setting the


On 11/9/12 3:58 AM, "Mike O'Neill" <michael.oneill@baycloud.com> wrote:

>I like this because, as you say, we can already do it in headers or
>javascript and we have a tried & tested spec covering it. It is also more
>transparent that doing it all in JS because you can see the _dnt_ cookie
>retained logs. If users delete all their cookies then they must mean they
>want to return to DNT: 1, so that's fine.
>The necessary extra API to cover 3rd parties would need to take account of
>web-wide exceptions. If a WWE was in place would we let a first-party
>override it? I think we would in order to be consistent with the idea that
>responsibility (for getting consent) is with the first-party site. In that
>case we would not change the value of the _dnt_ cookie in the third-party
>domain, just temporarily stop its transmission in the cookies: header when
>the request is for a third-party in the context of the responsible
>first-party site.
>The _dnt_ value could encode further qualifiers (like my f=toplevel.com,
>Thomas's WhoSetIt=<string> etc.) if we want.
>I did not understand your last sentence. What did you mean by "regular
>-----Original Message-----
>From: Roy T. Fielding [mailto:fielding@gbiv.com]
>Sent: 08 November 2012 19:39
>To: Shane Wiley
>Cc: Walter van Holst; public-tracking@w3.org
>Subject: Re: ISSUE-187 - some thoughts on using javascript
>I think you are both right, but talking past one another.
>What we effectively have now is a javascript API that sets a special named
>cookie that has no expiration date and a separate management interface.
>That can be accomplished via a header field instead of (or in addition to)
>javascript, and there are reasons to do so that mirror the Set-Cookie
>For example, the server could send
>   Set-DNT: 0
>to set an exception for its own domain, and perhaps include a list of
>domains for the other cases.  This works because we are now assuming that
>the server has performed the UI bit and the browser does not have a
>meaningful error case (either it sets the flag or it doesn't, and we won't
>know until the next applicable request).
>Now, I look at that and wonder why we don't just use a standard cookie
>and be done, as I suggested in Santa Clara.
>   Set-Cookie: _dnt_="0"
>If we did, then a UGE request would be something like
>   DNT: 1
>   Cookie: _dnt_="0"
>In other words, the DNT field would always reflect the global setting and
>the cookie would override for the sake of exception/permissions.
>If the cookie is deleted then it would have the same effect as the user
>deciding to clear all exceptions.  We could also define a special API for
>requesting that specific cookie be set for third-party domains, and UAs
>want to implement DNT exceptions can apply special UIs to their management
>that would avoid the regular reset actions.
>On Nov 8, 2012, at 9:49 AM, Shane Wiley wrote:
>> Walter,
>> The User Agent developers in the Working Group have already suggested
>will not build a UI here and Industry has already suggested they would not
>support DNT if they feel a UI does not provide a fair and balanced
>experience to the user.  The proposal from Adrian (and to some degree I
>believe, Ian) has such strong support broadly across the Working Group due
>to these issues.
>> I agree the user experience will be slightly different across Servers
>(including the need to remain accessible) but I believe that is the RIGHT
>outcome as each Server has a different value proposition, user experience,
>and intake flow than other sites so it makes sense this be different.
>> - Shane
>> -----Original Message-----
>> From: Walter van Holst [mailto:walter.van.holst@xs4all.nl]
>> Sent: Thursday, November 08, 2012 9:59 AM
>> To: public-tracking@w3.org
>> Subject: ISSUE-187 - some thoughts on using javascript
>> During yesterday's call either my poor command of the English language
>the equally poor service of Skype caused me not to make any sense on this
>issue, so I'll do it by e-mail.
>> After having put some thought in it, I am not in favour of using
>JavaScript for granting exceptions/permissions for overriding DNT:1 and
>several reasons:
>> Consistency:
>> - The general expression is already done through HTTP headers, so why
>have specific expression through HTTP too?
>> - Presentation to the user will be site-specific, which does not
>>provide a
>consistent user experience.
>> Accessibility:
>> - It puts more of a burden for sites who implement DNT to retain
>accessibility (e.g. ADA-requirements) while the UA can take care of this
>one go anyway. Smoothness of a few implemenations compared to thousands.
>> User control:
>> - It will be much harder for users to automate responses to requests for
>exceptions/permissions that use a Turing-complete language and will
>therefore come in all forms and shapes.
>> So basically, I would prefer to have this done at the HTTP and not the
>HTML level. If we insist on using JavaScript/ECMAscript then I would
>the standard to contain normative language for mandatory identifiers for
>such requests that make them machine-recognisable (my use of the term
>machine-readable during yesterday's call was in error and caused
>and allow for automated responses.
>> Regards,
>>  Walter
Received on Friday, 9 November 2012 13:18:30 UTC

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