Lookup for FHIR R4 UsageContext for use in FHIR R4B

Source ElementUsageTarget
UsageContext.idUseElementSameNameUsageContext.id
UsageContext.extensionUseElementSameNameUsageContext.extension
UsageContext.codeUseElementSameNameUsageContext.code
UsageContext.value[x]UseElementSameNameUsageContext.value[x]