This is the ValueSet that contains all the codes in MediaType (https://smt.esante.gouv.fr/fhir/ValueSet/jdv-hl7-v3-MediaType-cisis) and MediaType (https://smt.esante.gouv.fr/fhir/ValueSet/jdv-hl7-v3-MediaType-cisis). E.g. what you have to deal with if you get resources containing codes in either of them