{"id":"avro-no-default-sentinel","text":"_NO_DEFAULT is a sentinel object distinguishing \"no default provided\" from a None/null default; this matters because null is a valid Avro default value, and conflating the two would break canonical form computation and default-filling during resolution.","truth_value":"IN","source":"entries/2026/05/29/avro-serializer-avro_serializer.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{"example":"_NO_DEFAULT = object()\n# distinguishes \"no default\" from \"default is None\""},"explanation":{"steps":[{"node":"avro-no-default-sentinel","truth_value":"IN","reason":"premise"}]}}