We will be adding guidance around the appropriate use of the various exchange mechanisms.  The use of CommunicationRequest vs. Task will be covered.  CommunicationRequest is generally used when there's a need for a formal authorization or there's a need to describe aspects of the data to be shared that can be expressed by CommunicationRequest and can't easily be done by Task.  If using Task, there's no need for Communication because Task serves to link request and response.  If using CommunicationRequest without Task to seek fulfillment, Communication may sometimes be needed to establish a linkage between the request and the data sharing event that satisfies that request.