Following the discussions of the previous week, the issue of how to deal with conflict-free turn taking in making proposal and counterproposals was discussed. The updated state diagram in the draft including the "counteroffer pending" state addresses this issue.

In the context above, the issue of renegotiating existing CPAs was raised.

This led to the discussion of how to identify individual offers and how they relate to each other. The proposal of using the existing CPA ID and version numbers for offers was considered problematic as the version numbers are intended to indicate subsequent versions of (complete) CPAs.

It was assumed that offer ID can be additional payload of the negotiation messages.

Nicola raised the issue of how tightly the negotiation standard should be associated with CPA. It was agreed that, in a first step, tight coupling to CPA is easier but that generalization can be addressed subsequently.

Hima raised the issue whether complete CPAs should be sent as payloads of negotiation messages. There was consensus that presumably, for bootstrapping, the initial CPA must be send or the CPA template be known in advance by moth parties. Subsequently, changes and choices should be sufficient.

NDDs describe the constraints of one party with respect to what is negotiable. With respect to a parties own CPP part of the CPA, the NDD contains information on what can be negotiated. What is not mentioned is fixed. Referring to the CPA part of the other party, constraints can be defined on some elements. Not referring to elements of the other party’s CPP part means the first party doesn’t care.

Do we need non-binding as well as binding negotiation interaction? The initial negotiation patter foresaw both, but for a simple technical negotiation we might not need this distinction.