Glossary
What is FHIR implementation guide?
A FHIR implementation guide (IG) is a published bundle of profiles, value sets, code systems, examples, and narrative documentation that describes how to use FHIR for a specific purpose.
In context
Examples include US Core (US healthcare interoperability), International Patient Summary (cross-border patient summary), ISiK (German hospital exchange), MII (German research data), Da Vinci (US payer-provider data exchange), and many domain-specific guides.
An IG is the package of constraints, vocabularies, and conventions a deployment commits to when integrating with the relevant ecosystem. Conformance to an IG is what makes FHIR exchange interoperable in practice.
How Fire Arrow handles it
Fire Arrow stores standard FHIR R4 with profile validation. Conformance to a specific IG is a configuration and validation question; the data model does not change.