Background While we agree with the commenter that it would be ideal to reference a specific standard FHIR extension, there is no single choice or consensus on which one is preferred.  The extension the commenter references uses codes to define protocols and references an extensible binding with a single concept.  We think more appropriate choices for protocols include these FHIR standard extensions: http://hl7.org/fhir/StructureDefinition/workflow-adheresTo * http://hl7.org/fhir/StructureDefinition/workflow-instantiatesUri* http://hl7.org/fhir/StructureDefinition/workflow-instantiatesCanonical ... and for number of measurements:  CardX  “Number of Measurements” Extension: http://hl7.org/fhir/uv/cardx-htn/StructureDefinition/NumberOfMeasurementsExt   Tentative Decision ( Needs Discussion): 1. For protocols, update the Profile Specific Implementation Guidance bullet to: Information about the protocol  SHOULD  be supplied in either: Observation.note.text  (for example, “24-hour ambulatory measurement.”) the standard FHIR extension http://hl7.org/fhir/StructureDefinition/workflow-adheresTo   from FHIR extensions pack     the other FHIR standard listed are deprecated in future versions of FHIR? 2. for number of measurements, use a component to represent the count.  Issues: no standard LOINC or SNOMED CT code for the concept "number of measurements". ( Need to check HL7 vocabularies) average = sum of measures/number of measurements value is integer the benefit of being an inline element, not an extension. no MS or Additional USCDI Extension update examples