BPMN2 — Merge Conversation and Collaboration

Conversation and Collaboration currently differ because Conversation
messages can grouped, and Conversation can be reused. Since these
capabilities are useful on collaboration, it would be simpler for users
and implementers to merge these diagrams. Then there would be two
interactions diagrams, one highlighting communication between
participants (collaboration/conversation) and one highlighting the
sequence of message flow (Choreography). This would be easier to
explain and reduce the terminology complexity of the "three C models".

The resolution of issue 14654 will resolve this issue
Disposition: Duplicate