This is the ValueSet that contains all the codes in Questionnaire Item Collapsible (http://hl7.org/fhir/uv/sdc/ValueSet/collapsible) and Questionnaire Item Collapsible (http://hl7.org/fhir/uv/sdc/ValueSet/collapsible). E.g. what you have to deal with if you get resources containing codes in either of them