| Code | Display | Definition |
| complete-questionnaire | Complete Questionnaire | Code indicating a request to complete the a questionnaire - e.g. by Task or ServiceRequest
|
| questionnaire | Questionnaire | A canonical reference (possibly version-specific) to the Questionnaire to be completed
|
| questionnaire-response | Questionnaire Response | A reference to the QuestionnaireResponse resulting from the requested action
|
| response-endpoint | Response Endpoint | Identifies the base URL for FHIR servers to which the Questionnaire resulting from the Task should be POSTed
|
| question-library | Question Library | Indicates that a Questionnaire is a library of reusable items to be referenced during modular form assembly.
|
| behaviorExpressionLanguage | Behavior Expression Language | Application feature code for declaring supported language for behavior-related Questionnaire extensions (as categorized in the [expressions.html#table](SDC Extensions page table)). The feature value will be a supported expression mime type - text/cql, text/fhirpath, or application/x-fhir-query.
|
| extractionExpressionLanguage | Extraction Expression Language | Application feature code for declaring supported language for extraction-related Questionnaire extensions (as categorized in the [expressions.html#table](SDC Extensions page table)). The feature value will be a supported expression mime type - text/cql, text/fhirpath, or application/x-fhir-query.
|
| populationExpressionLanguage | Population Expression Language | Application feature code for declaring supported language for population-related Questionnaire extensions (as categorized in the [expressions.html#table](SDC Extensions page table)). The feature value will be a supported expression mime type - text/cql, text/fhirpath, or application/x-fhir-query.
|