What's Your Take On RfP Versus RfS?

Hi everybody. I'd like to get your opinion on the discussion about RfP versus RfS (Request for Solution). How do you see the difference?

I am always using the term RfP for the activities to invite a vendor to provide an offer for solving business issues. So as part of an RfP, we at Forrester describe the problem, the current state (CMO = Current Mode of Operation) and the to-be-expected future state (FMO = Future Mode of Operation). Despite the fact that we may describe the client's intention of the future state, we always ask invited providers to propose alternative solutions to the problem.

In this respect, I am currently reluctant to accept that we need another term besides RfT, RfI, RfQ, or RfP. From my experience, RfQ and RfP are the two things that differentiate between a commoditized service where you describe what the supplier has to deliver and an RfP in which you ask for a more "solution-oriented" proposal from the supplier. Rather than complicating things by adding new acronyms, I think it would be much better to use existing, well-established terms to differentiate between what we are looking for as a supplier's response.

Thanks for your comments.