Indirect DNT Processing (Proposed)

TPWG,

I was asked to develop language for consideration of how to manage DNT signals within Real-Time Bidding (RTB) environments such as an Ad Exchange.  I've up-leveled the concept to "Indirect DNT Processing" to cover scenarios where a user's signal may move from a direct client interaction to one between servers (server-to-server).

[Normative]
For Servers in direct communication with the User Agent that then communicate further with other parties within the same transaction but outside direct communication with the User Agent, those Servers MUST convey the current DNT flag relayed to their domain to those other parties.  In cases where other parties have recent knowledge of their own domain's DNT flag or UGE MAY process the request leveraging that information but MUST respond appropriately in the status response that they have done so - which, in turn, MUST then be conveyed by the Server to the User Agent.

[Non-Normative]
This is intended to facilitate indirect communications through a transitive passing of permission to allow for DNT processing to occur even when a processor doesn't have direct access to the User Agent.  If the processor has direct information about their own domain's DNT setting with the User Agent, such as their last direct interaction with the User Agent, they may want to consider this in their transaction handling.

Question - While from a policy perspective the passage of the STATUS RESPONSE value makes sense I'm not sure if this works as cleanly with the current TPE handling of those statuses.  Should we add a new flag/field to state a response is being conveyed from another party as to not confuse the User Agent into thinking the response is coming from the server in which it is in direct communication?

- Shane