This is the CodeSystem that contains all the codes in BRAlergenosCBARA (https://terminologia.saude.gov.br/fhir/CodeSystem/BRAlergenosCBARA) and BRAlergenosCBARA (https://terminologia.saude.gov.br/fhir/CodeSystem/BRAlergenosCBARA). E.g. what you have to deal with if you get resources containing codes in either of them