OptionalCodedOptionalDateOptionalDigitalOptionalDigitalOptionalEnvelopeOptionalKeywordsSearchable subject terms for image content. MWG composite tag that reconciles IPTC:Keywords and XMP-dc:Subject. Multi-value fields use semicolon-space ('; ') separators when represented as string. IPTC constraint: max 64 characters per keyword. Character encoding depends on IPTC:CodedCharacterSet; UTF8 recommended.
OptionalTime
See
https://exiftool.org/TagNames/IPTC.html