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Re: [wmlprogramming] Verizon, guidelines

From: Francois Daoust <fd@w3.org>
Date: Mon, 05 Jan 2009 14:20:28 +0100
Message-ID: <4962091C.9010001@w3.org>
To: Luca Passani <passani@eunet.no>
CC: public-bpwg-ct <public-bpwg-ct@w3.org>

Hi Luca,

I apologize for the shortness of my first message and the lack of 
responses afterwards.
I was off and actually managed not to have a look at my emails up until 
today...


Luca Passani wrote:
>>>>> Very well. Can someone from W3C comment? can I safely state that 
>>>>> W3C thinks that developers should had no-transform to their mobile 
>>>>> applications if they do not want their content transcoded under any 
>>>>> circumstances?
>>
>> Anyone? I think that Rigo's advice covers this myself, but can anyone 
>> else clarify?
> Yes. Come on, W3C. You have been discussing around this for one year 
> now. Does the Stetement above reflect CTG or not?
> 
> OK, I will fix it for you. 24 hours from now, if no evidence for the 
> contrary has been provided, I will assume that the above statement is 
> true and publicly state that, according to W3C, if mobile developers 
> want to protect their application from transcoders, they should modify 
> their applications and start using no-transform.

Technically speaking, there is no "W3C position" yet since the document 
is still a draft. There are personal opinions and an intermediary 
published position that represents a consensus in the task force at a 
given time. This intermediary position is not final.

The only official position I can think of is in the HTTP RFC 2616:
  http://www.ietf.org/rfc/rfc2616.txt
... section "14.9.5 No-Transform directive".

It does state that "Cache-Control: no-transform" is the standard way to 
prevent content modifications under any circumstances.
As of today, the directive is not respected by all the existing content 
transformation proxies, and is unfortunately (incorrectly, some would 
say) respected by some gateways, preventing WML to WMLC conversion 
and/or other optimizations that are useful on mobile networks. It is 
still the existing standard mechanism to prevent content transformation 
in any case.

We cannot be more prescriptive than the HTTP RFC, but we may precise 
good practices for some specific circumstances. In particular, I do not 
like the idea that this directive becomes the de facto required 
directive for mobile content. Mandating the respect of some heuristics 
(typically the use of e.g. XHTML MP, XHTML Basic, WML doctypes) is still 
under discussion. I personally think it should be part of the 
guidelines, in the absence of any better way for content providers to 
express their position regarding content transformation.

Francois.
Received on Monday, 5 January 2009 13:21:06 GMT

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