This is the ValueSet that contains all the codes in Insurance item type (http://hl7.org/fhir/us/davinci-drug-formulary/ValueSet/InsuranceItemTypeVS) and Insurance item type (http://hl7.org/fhir/us/davinci-drug-formulary/ValueSet/InsuranceItemTypeVS). E.g. what you have to deal with if you get resources containing codes in either of them