Da Vinci - Coverage Requirements Discovery
2.2.0-snapshot - STU 2.2 Peer Review

Da Vinci - Coverage Requirements Discovery, published by HL7 International / Financial Management. This guide is not an authorized publication; it is the continuous build for version 2.2.0-snapshot built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/davinci-crd/ and changes regularly. See the Directory of published versions

## Extension: Request Category

Official URL: http://hl7.org/fhir/us/davinci-crd/StructureDefinition/ext-request-category | Version: 2.2.0-snapshot | Highlight text changes?
Standards status: Trial-use Active as of 2026-02-19 | Maturity Level: 1 | Computable Name: RequestCategory
Other Identifiers: OID:2.16.840.1.113883.4.642.40.18.42.51

A high-level categorization of the type of request

Context of Use

This extension may be used on the following element(s)

- Element ID: `DeviceRequest`
- Element ID: `NutritionOrder`
- Element ID: `VisionPrescription`

Usage info

Usages:

- Use this Extension: CRD Device Request, CRD Nutrition Order and CRD Vision Prescription
- Examples for this Extension: DeviceRequest/example

You can also check for usages in the FHIR IG Statistics

### Formal Views of Extension Content

Description Differentials, Snapshots, and other representations.

- Differential Table
- Snapshot Table
- Statistics/References
- All

Name | Flags | Card. | Type | Description & Constraints Filter: Bindings Constraints Obligations
--- | --- | --- | --- | ---
Extension |  | 0..* | Extension | Request Category
extension |  | 0..0 |  | Extension
url |  | 1..1 | uri | "http://hl7.org/fhir/us/davinci-crd/StructureDefinition/ext-request-category"
value[x] |  | 0..1 | CodeableConcept | Value of extension
Documentation for this format

Name | Flags | Card. | Type | Description & Constraints Filter: Bindings Constraints Obligations
--- | --- | --- | --- | ---
Extension |  | 0..* | Extension | Request Category
id |  | 0..1 | string | Unique id for inter-element referencing
extension |  | 0..0 |  | Extension Slice: Unordered, Open by value:url
url |  | 1..1 | uri | "http://hl7.org/fhir/us/davinci-crd/StructureDefinition/ext-request-category"
value[x] |  | 0..1 | CodeableConcept | Value of extension
Documentation for this format

#### Constraints

Id | Grade | Path(s) | Description | Expression
ele-1 | error | **ALL** elements | All FHIR elements must have a @value or children | `hasValue() or (children().count() > id.count())`
ext-1 | error | **ALL** extensions | Must have either extensions or value[x], not both | `extension.exists() != value.exists()`

Summary

Simple Extension with the type CodeableConcept: A high-level categorization of the type of request

Maturity: 1

Differential ViewDifferential View

Name | Flags | Card. | Type | Description & Constraints Filter: Bindings Constraints Obligations
--- | --- | --- | --- | ---
Extension |  | 0..* | Extension | Request Category
extension |  | 0..0 |  | Extension
url |  | 1..1 | uri | "http://hl7.org/fhir/us/davinci-crd/StructureDefinition/ext-request-category"
value[x] |  | 0..1 | CodeableConcept | Value of extension
Documentation for this format

Snapshot View

Name | Flags | Card. | Type | Description & Constraints Filter: Bindings Constraints Obligations
--- | --- | --- | --- | ---
Extension |  | 0..* | Extension | Request Category
id |  | 0..1 | string | Unique id for inter-element referencing
extension |  | 0..0 |  | Extension Slice: Unordered, Open by value:url
url |  | 1..1 | uri | "http://hl7.org/fhir/us/davinci-crd/StructureDefinition/ext-request-category"
value[x] |  | 0..1 | CodeableConcept | Value of extension
Documentation for this format

#### Constraints

Id | Grade | Path(s) | Description | Expression
ele-1 | error | **ALL** elements | All FHIR elements must have a @value or children | `hasValue() or (children().count() > id.count())`
ext-1 | error | **ALL** extensions | Must have either extensions or value[x], not both | `extension.exists() != value.exists()`

Summary

Simple Extension with the type CodeableConcept: A high-level categorization of the type of request

Maturity: 1

Other representations of profile: CSV, Excel, Schematron