This is the ValueSet that contains all the codes in Reason(s) for substitution within second-line regimen ValueSet (http://smart.who.int/hiv/ValueSet/HIV.D.DE488) and Reason(s) for substitution within second-line regimen ValueSet (http://smart.who.int/hiv/ValueSet/HIV.D.DE488). E.g. what you have to deal with if you get resources containing codes in either of them