This is the ValueSet that contains all the codes in PurposeOfUse (http://terminology.hl7.org/ValueSet/v3-PurposeOfUse) and V3 Value SetPurposeOfUse (http://terminology.hl7.org/ValueSet/v3-PurposeOfUse). E.g. what you have to deal with if you get resources containing codes in either of them