Union of http://terminology.hl7.org/CodeSystem/UC and http://terminology.hl7.org/CodeSystem/UC
This is the CodeSystem that contains all the codes in UCDS (http://terminology.hl7.org/CodeSystem/UC) and UCDS (http://terminology.hl7.org/CodeSystem/UC). E.g. what you have to deal with if you get resources containing codes in either of them