Given that many areas of the FHIR specification are still undergoing Trial Use by the HL7 Community, and hence are not ready for balloting as a formal ANSI standard, and in order to manage the processes around the ballot process, four specific portions of this specification are considered as Normative Specifications:
| Infrastructure | The core framework on which FHIR solutions depend (Abstract base types, data types, formats, the RESTful API, and content and typing rules) |
|---|---|
| Conformance | The terminology infrastructure and the base resources that define FHIR implementations and that represent how the specification, and conformance to it, is defined |
| Patient | The Patient resource and related content |
| Observation | The Observation resource and related content |
Given that the Normative parts of the standard are still a subset of what implementers need to use, implementers are generally focusing on conforming to FHIR R4 as a whole rather than the formal standards. Future versions of this specification will extend the coverage of format standards.