This is the ValueSet that contains all the codes in CH ELM Interpretation Codes TITER (http://fhir.ch/ig/ch-elm/ValueSet/ch-elm-interpretation-codes-titer) and CH ELM Interpretation Codes TITER (http://fhir.ch/ig/ch-elm/ValueSet/ch-elm-interpretation-codes-titer). E.g. what you have to deal with if you get resources containing codes in either of them