http://hl7.org/fhir/StructureDefinition/specimen-reject-reason|5.2.0

References a resource or provides a code or text that specifies a substance that is added to a laboratory specimen (part of the container device or added to the specimen indenpendently).
element_idtypes
Extension
Extension.extension
Extension.url
Extension.value[x]
Extension
Extension.id
Extension.extension
Extension.url
Extension.value[x]