The section on Provenance isn't sufficiently clear.  What does the Provenance need to reflect?  What data elements are mandatory vs. optional?  Do we want one Provenance per query performed?  Per question asked?  What is the objective?  (If you make something a SHOULD, you need to provide an explanation of the benefits doing it and the costs of not  doing it when they're not obvious - and they're not obvious here.)  Does Provenance get stored on the Payer as part of the DocumentReference for work-in-progress?  How is it recorded in the EHR as part of the final results (whether QuestionnaireResponse or DocumentReference?  Are we using a transaction?  The 'header' Provenance mechanism?  A separate RESTful call?  Also "the source of the rules" is totally ambiguous.  We need standard 'labels' for each of the four system types involved in the DTR workflow and need to use those consistently throughout the spec.  E.g. "Light DTR client" (uses SMART app), "Full DTR client" (no smart app), "DTR Smart app", and "DTR payer".