generated: '2026-07-24'
method: derived
source: fhir/ncts-terminology-server-capabilitystatement.json + HL7 FHIR R4 resource model
note: >-
  Entity-relationship model of the FHIR terminology resources served by the NCTS FHIR
  Terminology Server, derived from the resources listed in its CapabilityStatement and
  the standard FHIR R4 references between them.
entities:
  - name: CodeSystem
    interactions: [read, search-type]
    description: Defines a set of concepts with codes, displays and properties (e.g. SNOMED CT-AU, AMT, LOINC).
  - name: ValueSet
    interactions: [read, search-type]
    operations: [$expand, $validate-code]
    description: Selects a set of codes drawn from one or more CodeSystems for a particular use.
  - name: ConceptMap
    interactions: [read, search-type]
    operations: [$translate]
    description: Maps concepts between a source and target ValueSet/CodeSystem.
  - name: StructureDefinition
    interactions: [read, vread, search-type, create, update, patch, delete, history-instance, history-type]
    description: Defines FHIR structures, profiles and extensions.
  - name: OperationDefinition
    interactions: [read]
    description: Defines the terminology operations supported by the server.
relationships:
  - from: ValueSet
    to: CodeSystem
    type: has_many
    via: compose.include.system
    note: A ValueSet includes/excludes concepts drawn from one or more CodeSystems.
  - from: ConceptMap
    to: ValueSet
    type: belongs_to
    via: sourceUri / targetUri
    note: A ConceptMap references source and target ValueSets (or CodeSystems).
  - from: ConceptMap
    to: CodeSystem
    type: belongs_to
    via: group.source / group.target
  - from: CodeSystem
    to: ValueSet
    type: has_one
    via: valueSet
    note: A CodeSystem may reference a ValueSet enumerating all its concepts ("all codes").
  - from: StructureDefinition
    to: ValueSet
    type: has_many
    via: element.binding.valueSet
    note: Element bindings reference ValueSets for coded values.