This is the ValueSet that contains all the codes in CMS Place of Service Codes (POS) (http://terminology.hl7.org/ValueSet/CMSPlaceOfServiceCodes) and CMS Place of Service Codes (POS) (http://terminology.hl7.org/ValueSet/CMSPlaceOfServiceCodes). E.g. what you have to deal with if you get resources containing codes in either of them