This is the ValueSet that contains all the codes in DaVinci ATR Change Types (http://hl7.org/fhir/us/davinci-atr/ValueSet/atr-changetype) and DaVinci ATR Change Types (http://hl7.org/fhir/us/davinci-atr/ValueSet/atr-changetype). E.g. what you have to deal with if you get resources containing codes in either of them