The dictionary of the Exif tags

Name Tag	Description
Byline	The name of the creator of the image, e.g. artist, photographer, etc.
BylineTitle	The byline title (e.g. staff photographer, correspondent, etc).
Caption	The textual description of the image.
Category	The image category.
City	The city of the image origin.
CopyrightNotice	The copyright notice.
Country	The country of the image origin.
Credit	The provider of the image.
DateCreated	The date the image (as an intellectual content, rather than physical file) created.
Headline	The brief overview for the image.
Keyword	The keywords used for search.
ObjectName	The short reference for the object.
OriginalTransmissionReference	The location of the original transmission.
Source	The original owner of the intellectual content of this image.
SpecialInstructions	Some custom editorial instructions.
State	The state/province of the image origin.
SupplementaryCategory	The supplementary category for the image.
Urgency	The editorial urgency of the content.
Writer	The name of editor or other person involved in the writing.