knowable property
Knowable is when THIS PLANE could first have answered with the assertion: the later of Seen and the server clock at the write, derived server-side. It is the instant the leakage guard compares, so it is published beside the claim it was derived from — an answer whose rule nobody can see is one nobody can check.
Please note: This property should have been non-nullable! Since the specification file does not include a default value (using the "default:" property), however, the generated source code must fall back to having a nullable type. Consider adding a "default:" property in the specification file to hide this note.
Implementation
String? knowable;