This is the ValueSet that contains all the codes in Family Member Value (http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113883.1.11.19579) and FamilyMember (http://terminology.hl7.org/ValueSet/v3-FamilyMember). E.g. what you have to deal with if you get resources containing codes in either of them