http://hl7.org/fhir/StructureDefinition/devicerequest-patientInstruction|5.2.0

Simple concise instructions to be read by the patient. For example “twice a day” rather than “BID.”.
typedestination
baseDefinitionhttp://hl7.org/fhir/StructureDefinition/Extension
typehttp://hl7.org/fhir/StructureDefinition/Extension
Extension.extension.typehttp://hl7.org/fhir/StructureDefinition/Extension
Extension.extension.url.typehttp://hl7.org/fhir/StructureDefinition/uri
Extension.extension.value[x].typehttp://hl7.org/fhir/StructureDefinition/code
Extension.extension.value[x].binding.valueSethttp://hl7.org/fhir/ValueSet/languages
Extension.extension.typehttp://hl7.org/fhir/StructureDefinition/Extension
Extension.extension.url.typehttp://hl7.org/fhir/StructureDefinition/uri
Extension.extension.value[x].typehttp://hl7.org/fhir/StructureDefinition/string