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