rank
A QDM attribute provides specific detail about a QDM datatype.
rank defines a position in a hierarchy for diagnoses or procedures. It replaces ordinality previously assigned to "Procedure, Performed", "Procedure, Order", and "Procedure, Recommended". ordinality does not align with any FHIR resources; it does align with definitions for FHIR encounter.diagnosis. Thus, the concept fits best consistently across QDM for the concept of principal for encounter diagnosis and for procedure.