Re: PF comments on Guidelines for Web Content Transformation Proxies 1.0 ( LC-2358 LC-2359 LC-2360)

This is second follow up to your response to PFWG comments on Web
Content Transformation Proxies. Our first response was sent 17 February
<http://lists.w3.org/Archives/Public/public-bpwg-comments/2010JanMar/0012.html>,
but we were unable at the time to respond to one of your responses. We
now have the response to that one. PFWG agreement to send this response
is recorded at http://www.w3.org/2010/03/03-pf-minutes.html#item05.

PFWG accepts LC-2359 because the issue is with the HTTP spec, not with
WCTP. We can identify use cases where the specified behavior is
problematic for accessibility, but acknowledge that there are others
where it is necessary. PFWG will take up the concern with HTTP in other
channels.

Michael

fd@w3.org wrote:
>  Dear Michael Cooper ,
>
> The Mobile Web Best Practices Working Group has reviewed the comments you
> sent [1] on the Last Call Working Draft [2] of the Guidelines for Web
> Content Transformation Proxies 1.0 published on 6 Oct 2009. Thank you for
> having taken the time to review the document and to send us comments!
>
> The Working Group's response to your comment is included below, and has
> been implemented in the new version of the document available at:
> http://www.w3.org/TR/2010/WD-ct-guidelines-20100211/.
>
> Please review it carefully and let us know by email at
> public-bpwg-comments@w3.org if you agree with it or not before 11 March
> 2010. In case of disagreement, you are requested to provide a specific
> solution for or a path to a consensus with the Working Group. If such a
> consensus cannot be achieved, you will be given the opportunity to raise a
> formal objection which will then be reviewed by the Director during the
> transition of this document to the next stage in the W3C Recommendation
> Track.
>
> Thanks,
>
> For the Mobile Web Best Practices Working Group,
> Dominique Hazaël-Massieux
> François Daoust
> W3C Staff Contacts
>
>  1. http://www.w3.org/mid/4B423E4F.1060004@w3.org
>  2. http://www.w3.org/TR/2009/WD-ct-guidelines-20091006/
>
>
> =====
>
> Your comment on the document as a whole:
>   
>> >From the introductory text and clauses such as 4.2.7 through 4.2.9, it
>> is clear that this is targeted at proxies that are transcoding content
>> for mobile devices yet the title sounds like it's targeted at any kind
>> of transformation proxy. Suggest changing the title to more accurately
>> reflect the narrower scope.
>>     
>
>
> Working Group Resolution (LC-2358):
> We have debated about the title at length previously and this is the best
> title we could think of that remains in the title category and does not
> degenerate into a full abstract. We think that the abstract section
> precises the narrower scope under which the guidelines are to be read.
>
> ----
>
> Your comment on 4.2.3 Receipt of Cache-Control: no-transform:
>   
>> 4.2.3: If a website contains a "Cache-Control: no transform" directive,
>> proxies must NOT alter the content. Would this be a problem for a
>> proxy-based accessibility transcoding solution?
>>     
>
>
> Working Group Resolution (LC-2359):
> We agree that the "Cache-Control: no transform" directive is heavy handed
> but it is the only mechanism provided by RFC 2616. We have amplified the
> note in Appendix I.1.3 (the appendix provides informative guidance for
> Origin Servers and this section relates to the use of the "Cache-Control:
> no-transform" directive) to state that this directive can also disrupt the
> behavior of a proxy based accessibility solution.
>
> ----
>
> Your comment on 4.2.9.1 Alteration of Response:
>   
>> 4.2.9.1 #2: The altered content should validate to an appropriate
>> published formal grammar and be well-formed. Validation might be a
>> problem for an accessibility transcoding solution. Validation is not
>> part of WCAG 2.0 because sometimes adding in stuff that's not in the
>> DTD
>> can make something more accessible (like ARIA for example). Note that
>> this is a "should", not a "must".
>>     
>
>
> Working Group Resolution (LC-2360):
> We agree that there are cases when validation should not have to be
> enforced and note that this is precisely why the guideline is a "should":
> transcoding proxies may need to produce content that does not validate
> against a formal grammar "but the full implications must be understood and
> carefully weighed" (quoted from the definition of "should" in RFC 2119).
>
>
>
> ----
>
>
>
>   

-- 

Michael Cooper
Web Accessibility Specialist
World Wide Web Consortium, Web Accessibility Initiative
E-mail cooper@w3.org <mailto:cooper@w3.org>
Information Page <http://www.w3.org/People/cooper/>