Did you know that Norway's ISO country code is also valid YAML for False?— Christopher Neugebauer ️ (@chrisjrn) February 24, 2020
You Do Now.
JSON's RFC4627 requires that mappings keys merely “SHOULD” be unique, while YAML insists they “MUST” be. Technically, YAML therefore complies with the JSON spec, choosing to treat duplicates as an error. In practice, since JSON is silent on the semantics of such duplicates, the only portable JSON files are those with unique keys, which are therefore valid YAML files.
~) means NULL Source