Optionaltitle/Title → dc:title.
Optionalauthor/Author → dc:creator.
Optionalsubject/Subject → dc:description.
Optionalkeywords/Keywords → pdf:Keywords.
Optionalcreator/Creator (authoring app) → xmp:CreatorTool.
Optionalproducer/Producer (PDF producer) → pdf:Producer.
Optionalcreation/CreationDate (PDF date string) → xmp:CreateDate.
Optionalmod/ModDate (PDF date string) → xmp:ModifyDate.
The standard document-information fields (ISO 32000-1 §14.3.3), shared by the
/Infodictionary and the XMP/Metadatapacket. Passed to GigaPdfDoc.setInfo, which writes both and keeps them in sync. Every field is optional; onsetInfoan omitted field is left unchanged (a partial update). Dates are PDF date strings ("D:YYYYMMDDHHmmSS+HH'mm'").