Lookup for FHIR R5 UsageContext for use in FHIR R4

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