ACTION-678: Raise and issue on the distinction between a CT proxy and (say) Opera Mini

At the F2F meeting in Korea, I was given the action of getting some
discussion started on how the CT guidelines should handle CT solutions
that consist of both a CT proxy and a proprietary client.  I've been
derelict on doing anything about this, so I'd like to try and make
amends by getting something started now.

At the Korea F2F meeting, there was some discussion about what to do
about CT solutions that contain both a CT proxy and an associated,
proprietary client (Novarra has been doing this on various platforms for
years; Opera Mini is probably the best known example to the general
public).  No real resolution was reached and it was decided that we
should try to get some discussion going on the CT mailing list on this
topic.

I guess the question is:  should CT client/proxy solutions be required
to follow the same CT guidelines as CT proxy solutions?  The CT
guidelines as they currently exist only mention proxy solutions;
client/proxy solutions are not mentioned.

My opinion is that client/proxy solutions should be treated as mobile
browsers that just happen to be distributed across a client device and
server machine; i.e., the client and proxy are part of a browsing
solution in which neither is designed to work without the other, so they
must be treated as one entity.  I would argue that as far as content
providers are concerned, this entity is more like a browser than a
proxy.  Content providers would see the client/proxy combination as just
another mobile browser since they would never see the client by itself
without the proxy.  The client/proxy solution will have its own HTTP
request header values (including User-Agent) and any special mobile
content would need to be designed for the entire client/proxy
combination, not just the client.

Currently, users tend to install the client for these client/proxy
solutions themselves in addition to whatever native browser was
pre-installed on the device.  However, I think this is a side issue and
not really relevant as to whether these solutions need to follow the CT
guidelines.  A mobile operator could easily install a client/proxy
solution in their network--including the pre-installation of the client
on mobile devices that it resells.  (In fact, this has been done.)

It appears to me that the Mobile Web Best Practices Guidelines and the
MobileOK Basic Tests are the most relevant BPWG documents for
client/proxy solutions.  My opinion is that client/proxy solutions
should not be required to follow the CT Guidelines.

Sean