http://hl7.org/fhir/StructureDefinition/structuredefinition-hierarchy|4.0.1
For circular references (references back to the same type of resource): whether they are allowed to transitively point back to the same instance (false), or whether the relationship must be a strict one-way hierarchy (true).
description: 'For circular references (references back to the same type of resource): whether they are allowed to transitively point back to the same instance (false), or whether the relationship must be a strict one-way hierarchy (true).' derivation: constraint name: hierarchy type: Extension elements: extension: {index: 0} url: pattern: {type: Uri, value: 'http://hl7.org/fhir/StructureDefinition/structuredefinition-hierarchy'} index: 1 value: choices: [] index: 3 extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/StructureDefinition/structuredefinition-hierarchy base: http://hl7.org/fhir/StructureDefinition/Extension version: 4.0.1 required: [value]