f:Practitioner/f:identifier system: minimum cardinality of 'system' is 1 value: minimum cardinality of 'value' is 1 system: minimum cardinality of 'system' is 1 value: minimum cardinality of 'value' is 1 system: minimum cardinality of 'system' is 1 value: minimum cardinality of 'value' is 1 f:Practitioner/f:gender extension with URL = 'http://hl7.at/fhir/HL7ATCoreProfiles/4.0.1/StructureDefinition/at-core-ext-gender-administrativeGenderAddition': maximum cardinality of 'extension' is 1