http://hl7.org/fhir/StructureDefinition/codesystem-conceptOrder|5.2.0

Identifies the relative order in which concepts within the value set should be presented to a user. This extension has been deprecated and is not recommended for use as the purpose of this extension does not make sense for a code system.
typedestination
baseDefinitionhttp://hl7.org/fhir/StructureDefinition/Extension
typehttp://hl7.org/fhir/StructureDefinition/Extension
Extension.value[x].typehttp://hl7.org/fhir/StructureDefinition/integer