1.2.1 Metadata

We can add various bits of metadata in our document. For this purpose, we have to create an "Info" dictionary and refer to this object in the trailer dictionary to it with the name /Info.

All entries of this dictionary are optional (some are required for PDF standards):

Name	Type	Example entry	Required?
Title	String	(My holiday journey)	yes
Author	String	(Mr. Bean)	no
Subject	String	(Holiday plans for July)	no
Keywords	String	(holiday plans canne)	no
Creator	String	(Adobe Indesign)	no
Producer	String	(printpdf v.0.5.0)	no
CreationDate	DateString	(D:20170705215328+02'00')	yes
ModDate	DateString	(D:20170705215328+02'00')	yes
Trapped	Boolean	true	yes
GTS_PDFXVersion	String	(PDF/X-3:2002)	yes

What DateString refers to: The entry is still a PDF string, but in a spectial format:

D:%Y%m%d%H%M%S'%TZ'%tz

%TZ and %tz refer to the time zone as hours and minutes, respectively. These entries are only needed if the time is not in GMT. Some programs use this info to sort documents.

Please note that none of the above entries is required, they are only requried if you want to validate your PDF against a certain PDF standard.

Example:

1 0 obj
<<
/Title (Holiday plans)
/Author (Mr. Bean)
/Subject (After a won lottery, madman invades france)
/Keywords (cannes teddy holiday)
/Creator (MyPdfProgram)
/Producer (printpdf v.0.5.0)
/CreationDate (D:20110628115000+02'00')
/ModDate (D:20110628115000+02'00')
>>
trailer
<<
/Info 1 0 R
>>