This is the ValueSet that contains all the codes in Adverse Event Clinical Research Causality Relatedness (http://terminology.hl7.org/ValueSet/adverse-event-clinical-research-causality-relatedness) and Adverse Event Clinical Research Causality Relatedness (http://terminology.hl7.org/ValueSet/adverse-event-clinical-research-causality-relatedness). E.g. what you have to deal with if you get resources containing codes in either of them