### Conforming to AU Patient Summary

<div class="stu-note" markdown="1">
Work is underway in the [AU PS Conformance Sessions](https://confluence.hl7.org/spaces/HAFWG/pages/345082204/AU+Patient+Summary+Conformance+Sessions) on a [proposal for conformance](https://confluence.hl7.org/spaces/HAFWG/pages/345545963/AU+PS+Conformance+Requirements), including the definition of AU PS actors and obligations. Once agreed, this page will be updated, AU PS actors will be introduced, and AU PS profiles will be updated to include Obligations.

NOTE: There is no expectation that AU PS R1 will introduce capability statements
</div><!-- stu-note -->


The requirements of the FHIR standard and [FHIR Conformance Rules](http://hl7.org/fhir/conformance-rules.html) apply, and define the use of terms in this guide including the conformance verbs - **SHALL**, **SHALL NOT**, **SHOULD**, **SHOULD NOT**, **MAY**.

Implementers are advised to be familiar with the requirements of the FHIR standard and IPS when implementing AU PS, in particular:
- [IPS Generation and Data Inclusion](https://build.fhir.org/ig/HL7/fhir-ips/Generation-and-Data-Inclusion.html#generation-and-data-inclusion)
- [IPS Narrative and Language Translation](https://build.fhir.org/ig/HL7/fhir-ips/Design-Conventions.html#narrative-and-language-translation)
- [FHIR Terminology requirements](http://hl7.org/fhir/R4/terminologies.html)
- [FHIR Documents](https://hl7.org/fhir/R4/documents.html) 
- [FHIR RESTful API](http://hl7.org/fhir/R4/http.html) 
- [FHIR Search](http://hl7.org/fhir/R4/search.html)
- [FHIR Resource formats](http://hl7.org/fhir/R4/resource.html)
- [FHIR Data Types](http://hl7.org/fhir/R4/datatypes.html)

### Conformance Artifacts

#### AU PS Profiles and Extensions
The [Profiles and Extensions](profiles-and-extensions.html) page lists the AU PS profiles and extensions defined for this implementation guide. An AU PS profile [StructureDefinition](http://hl7.org/fhir/R4/structuredefinition.html) defines the minimum elements, extensions, vocabularies and value sets that **SHALL** be present and constrains the way elements are used when conforming to the profile.

AU PS profile elements include mandatory and *Must Support* requirements. [Mandatory elements](#mandatory-elements) are required and have a minimum cardinality of 1 (min=1). [Must Support](#must-support-and-obligation) elements have defined conformance obligations in AU PS.

### Mandatory Elements
Mandatory elements are elements with minimum cardinality > 0. When an element is mandatory, the data is expected to always be present. Very rarely, it may not be, and in this circumstance the requirements defined by AU Core for [Missing Data](https://build.fhir.org/ig/hl7au/au-fhir-core/general-requirements.html#missing-data) **SHALL** be applied. 

An element can be both *Must Support* and mandatory, in which case the requirements defined by AU Core for mandatory's Missing Data requirements **SHALL** be applied as described in [Missing Must Support and Mandatory Data](https://build.fhir.org/ig/hl7au/au-fhir-core/general-requirements.html#missing-must-support-and-mandatory-data).

The convention in this guide is to mark all mandatory elements as *Must Support* unless they are nested under an optional element.

### Must Support and Obligation
Labelling an element *[Must Support](https://www.hl7.org/fhir/conformance-rules.html#mustSupport)* means that systems that produce or consume resources **SHALL** provide support for the element in some meaningful way. The FHIR standard does not define exactly what 'meaningful' support for an element means, but indicates that a profile **SHALL** make clear exactly what kind of support is required when an element is labelled as *Must Support*.

TBD - to add defined and agreed actors.

#### Presentation of Must Support and obligation in profiles
TBD

#### Interpreting profile elements labelled Must Support
TBD

### Missing Data

There are situations when information for a particular data element is missing and the source system does not know the reason for the absence of data. 

#### Missing Must Support and Optional Data

If the source system does not know the value for an optional element (minimum cardinality = 0), including elements labelled *Must Support*, as per the requirements defined in [AU Core](https://build.fhir.org/ig/hl7au/au-fhir-core/general-requirements.html#missing-must-support-and-optional-data), the data element **SHALL** be omitted from the resource.  

#### Missing Must Support and Mandatory Data

If the data element is a mandatory element (minimum cardinality is > 0), the element **SHALL** be present *even if* the source system does not know the value or the reason the value is absent and the requirements defined by AU Core for [Missing Must Support and Mandatory Data](https://build.fhir.org/ig/hl7au/au-fhir-core/general-requirements.html#missing-must-support-and-mandatory-data) **SHALL** be applied.

### Suppressed Data
In some circumstances, specific pieces of data may be hidden due to security or privacy reasons and in these circumstances the requirements defined by AU Core for [Suppressed Data](https://build.fhir.org/ig/hl7au/au-fhir-core/general-requirements.html#suppressed-data) **SHALL** be applied.