This is the ValueSet that contains all the codes in NCPDP Reject Code Value Set (http://hl7.org/fhir/us/carin-bb/ValueSet/NCPDPRejectCode) and NCPDP Reject Code Value Set (http://hl7.org/fhir/us/carin-bb/ValueSet/NCPDPRejectCode). E.g. what you have to deal with if you get resources containing codes in either of them