Following discussion of https://jira.hl7.org/browse/FHIR-36521 - automatic storing needs to be required-
When I previously read about the Annotate card with its call out that a system action could automatically store the annotation, I had assumed that I would just parse the suggestions for the coverageGuidance extension and automatically file it- however, that was incorrect since CDS Hooks intends for Card suggestions to be something a user interacts with, and for the "systemActions" that automatically happen to be received at a higher level in the response, not as a child of any Card.

To clarify things, and to give a better amount of guidance since we've been discussing if this will be a SHALL, I propose we add:

A new section following 4.3.4 Cards http://hl7.org/fhir/us/davinci-crd/2022May/hooks.html#cards:

"
4.3.5 System Actions
System Actions are the mechanism used to return coverage requirements from the CRD Service to the CRD Client that should be auto-applied without user intervention.

4.3.5.1 Coverage Information
System Actions are the preferred method of sending the new FHIR coverage-information extension, capturing assertions from a CRD Service about whether the request is covered and/or requires prior authorization, what coverage the assertion is made with respect to, when the assertion was made, and optionally a trace id that can be used for audit purposes.

Note that Cards can be sent alongside System Actions, however if everything a CRD Service provides fits within the coverage-information extension, then no Card is needed (the CRD Client will instead use that discrete data as appropriate).

CRD Clients are responsible for determining the appropriateness of writing data from a systemAction to an order, as well as the best UI mechanism for informing provider staff of the information provided.

CRD Services that make assertions with respect to coverage and prior authorization SHALL provide a system action containing the coverage-information extension. Clients SHALL support receiving that extension.

For example, this response automatically flags that a service is not covered without requiring user intervention:

{
    "cards": [],
    "systemActions": [{
        "type": "update",
        "resource": {
            "resourceType": "ServiceRequest",
            "id": "example-procedure-123",
            "extension": [{
                "url": "http://hl7.org/fhir/us/davinci-crd/StructureDefinition/ext-coverage-information"
                "extension": [
                    {
                        "url": "coverageInfo",
                        "valueCoding": {
                            "system": "http://hl7.org/fhir/us/davinci-crd/CodeSystem/coverageGuidance",
                            "code": "not-covered",
                        }
                    },
                    {
                        "url": "coverage",
                        "valueReference": {
                            "reference": "Coverage/example-coverage-id"
                        }
                    },
                    {
                        "url": "date",
                        "valueDate": "2022-05-19"
                    },
                    {
                        "url": "identifier",
                        "valueString": "example-trace-number-123"
                    }
                ]
            } ],
            "...": "<ServiceRequest properties snipped for brevity>"
        }
    }]
}

"

And then in http://hl7.org/fhir/us/davinci-crd/2022May/hooks.html#annotate we could remove some of the current language around system action and instead link to the new more detailed section.

There is also some language about using a system action in http://hl7.org/fhir/us/davinci-crd/2022May/hooks.html#pre-emptive-prior-authorization- this could similarly get moved to a more detailed section, but I don't think it's too important to do right now since we aren't at a place where it's realistic to get those responses today.

See https://chat.fhir.org/#narrow/stream/180803-Da-Vinci-CRD/topic/System.20Action.20proposal for related zulip chat.