CDex contains as much, and sometimes more, of a detailed description of of the Information Exchange Interactions, Actors, and Actor Interaction Diagrams than HRex; however, CDex refers readers to the HRex implementaiton guide for more details.

Co-ordination must occur between the HRex and CDex IGs.

Given HRex is the umbrella IG, everything that is considered "standard" for all downstream IGs (i.e., CDex, PDex, DEQM) should be within HRex. That way the information does not have to be repeated and, possibly accidently modified which would cause burden on healthcare organizations. That would allow the downstream IGs to reference HRex and add their additional information if needed. This in turn, would reduce the need for software developers to compare and find the differences between the differnet DaVinci IGs.