Re: transcoders bad

I would love to hear a response to my response, since this is an
important point and one you are passionate about:

1) The guidelines specify that User-Agent's value is preserved in an
X-Device-User-Agent header, if modified. I am not sure how this is not
"preserved" then? Maybe you missed that part and this is good news.
Because on that, we agree -- no reason the information should not be

2) If you don't change the User-Agent, you're lying. The site is NOT
talking to a mobile device! it's talking to a transcoder. It is
important to tell the site, so that it can say "don't transcode" for
example. Did you reverse your statement? why would I serve a
no-transform directive if I *was* talking to a mobile phone directly?
it's only if I knew I was talking to a transcoder that I would. So,
preserving the User-Agent is harmful by this logic.

Sending back mobile-oriented content to a transcoder is likely worse
than sending back desktop content too. What's your answer to that? I
think it is a legitimate problem, from experience.

I do honestly look forward to understanding how you'd propose to avoid
this problem, for developers like Terren for example.

On Tue, Aug 5, 2008 at 4:23 AM, Luca Passani <> wrote:
>>  Hi Terren,
>> The CT Guidelines ensure that any mobile-aware content provider can have
>> *total control* over whether transcoding is used or not on content, by
>>  the use of standard HTTP features: See "4.2.2 Server Origination of
>>  Cache-Control: no-transform".
> It is not so, Brian. CT Guidelines do not demand that the User-Agent string
> has to be preserved. This means that a transcoder can use a web browser UA
> and a mobile site won't even know it is talking to a mobile device and will
> not know it can serve a "no-trasform" header to the device.
> More than that, even if the server served "No-trasform" headers
> unconditionally, it would still be getting the wrong User-Agent.
> So, please do not mud the water.
> Luca

Received on Tuesday, 5 August 2008 13:22:18 UTC