This is the ValueSet that contains all the codes in Evidence Variable Role Subtype Value Set (http://hl7.org/fhir/uv/ebm/ValueSet/evidence-variable-role-subtype) and Evidence Variable Role Subtype Value Set (http://hl7.org/fhir/uv/ebm/ValueSet/evidence-variable-role-subtype). E.g. what you have to deal with if you get resources containing codes in either of them