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