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