This is the set of resources that conform to either of the profiles Immunizations Section (http://hl7.org/cda/us/ccda/StructureDefinition/ImmunizationsSection) and Immunizations Section (http://hl7.org/cda/us/ccda/StructureDefinition/ImmunizationsSection). E.g. what you have to deal with if you get resources conforming to one of them