None: No Format (CSV, XLS, TXT, PDF, etc): https://www.iana.org/assignments/media-types/text/csv,https://www.iana.org/assignments/media-types/text/tab-separated-values,https://www.iana.org/assignments/media-types/application/rdf+xml,https://www.iana.org/assignments/media-types/application/xml,https://www.iana.org/assignments/media-types/application/json Formats: JSON