This is the ValueSet that contains all the codes in Route Of Administration (http://hl7.org/fhir/uv/emedicinal-product-info/ValueSet/routeOfAdministration) and Route Of Administration (http://hl7.org/fhir/uv/emedicinal-product-info/ValueSet/routeOfAdministration). E.g. what you have to deal with if you get resources containing codes in either of them