securityLabel property
securityLabel A set of Security-Tag codes specifying the level of privacy/security of the Document found at DocumentReference.content.attachment.url. Note that DocumentReference.meta.security contains the security labels of the data elements in DocumentReference, while DocumentReference.securityLabel contains the security labels for the document the reference refers to. The distinction recognizes that the document may contain sensitive information, while the DocumentReference is metadata about the document and thus might not be as sensitive as the document. For example: a psychotherapy episode may contain highly sensitive information, while the metadata may simply indicate that some episode happened.
Implementation
List<CodeableConcept>? get securityLabel =>
throw _privateConstructorUsedError;