description: Mark that an invariant represents 'best practice' rule - a rule that implementers may choose to enforce at error level in some or all circumstances. package_name: hl7.fhir.core derivation: constraint name: Mark a warning invariant as 'best practice' type: Extension elements: extension: index: 0 slicing: slices: extension: match: {} schema: {index: 0} max: 0 url: type: uri pattern: {type: Uri, value: 'http://hl7.org/fhir/StructureDefinition/elementdefinition-bestpractice'} index: 1 value: choices: [valueBoolean, valueCodeableConcept] index: 3 valueBoolean: {type: boolean, choiceOf: value, index: 4} valueCodeableConcept: {type: CodeableConcept, choiceOf: value, index: 5} package_version: 1.8.0 extensions: extension: {url: null, max: 0, index: 0} class: extension kind: complex-type url: http://hl7.org/fhir/StructureDefinition/elementdefinition-bestpractice base: http://hl7.org/fhir/StructureDefinition/Extension version: null required: [value, valueBoolean, valueCodeableConcept]