This is the ValueSet that contains all the codes in eCR MessageHeader Event Value Set (http://hl7.org/fhir/us/ecr/ValueSet/valueset-ecr-messageheader-event) and eCR MessageHeader Event Value Set (http://hl7.org/fhir/us/ecr/ValueSet/valueset-ecr-messageheader-event). E.g. what you have to deal with if you get resources containing codes in either of them