# Common Components FHIR Implementation Guide

26.0.0 - Trial

Common Components FHIR Implementation Guide, published by Australian Digital Health Agency. This guide is not an authorized publication; it is the continuous build for version 26.0.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/AuDigitalHealth/common-components/ and changes regularly. See the Directory of published versions

## Conformance

This page describes the conformance requirements for systems implementing this Implementation Guide.

## General Conformance Requirements

Systems implementing this Implementation Guide:

- SHALL support the FHIR R4 specification
- SHALL implement the profiles and extensions defined in this Implementation Guide when claiming conformance to this guide
- SHALL use the terminology defined in this Implementation Guide where specified

## Extension Conformance

When a system uses extensions defined in this Implementation Guide:

- The system SHALL be capable of including the extension in resource instances when the extension data is available
- The system SHALL interpret missing extension data as data not present in the sender's systems
- The system SHOULD be capable of processing resource instances containing extensions without generating an error

## Must Support

For profiles that utilize extensions from this Implementation Guide, Must Support on any data element SHALL be interpreted as follows:

- Sending systems SHALL be capable of including the data element in the resource instance if the data element is available
- Receiving systems SHALL be capable of processing resource instances containing the data element without generating an error or causing the application to fail
- Receiving systems SHOULD be capable of displaying the data element for human use or storing it for other purposes

## Extensions Processing

Systems implementing this Implementation Guide:

- SHALL be capable of processing resources containing extensions defined in this Implementation Guide
- SHALL ignore unrecognized extensions and continue processing
- SHOULD be capable of processing resources with extensions not defined in this Implementation Guide

## Terminology

Systems implementing this Implementation Guide:

- SHALL use the code systems and value sets defined in this Implementation Guide where specified
- SHOULD validate coded values against the appropriate value sets
- MAY use additional codes not defined in this Implementation Guide where permitted by binding strength

## Error Handling

Systems implementing this Implementation Guide:

- SHALL return appropriate HTTP status codes
- SHALL return OperationOutcome resources when appropriate
- SHOULD provide meaningful error messages to aid in debugging

## Missing Data

Implementers SHALL be able to handle cases where missing data exists. Where mandatory elements are missing, this will be indicated by the established convention in FHIR, i.e. supplying the extension `DataAbsentReason`.