This is the ValueSet that contains all the codes in Substance Administration Substitution Codes (http://fhir.ch/ig/ch-emed-epr/ValueSet/ch-emed-epr-substance-admin-substitution-code) and Substance Administration Substitution Codes (http://fhir.ch/ig/ch-emed-epr/ValueSet/ch-emed-epr-substance-admin-substitution-code). E.g. what you have to deal with if you get resources containing codes in either of them