Any document level Metadata.
The Metadata object holds XMP metadata such as Title, Author,
Subject, Keywords, Creator, Creation Date and Modification
There are multiple places that document level metadata can be
stored in a PDF. The most commonly used are the Info entry of the
Trailer and the Metadata entry of the Catalog.
The Info entry is the older and most widely recognized location.
The Metadata entry is a more recent XML based store introduced in
PDF 1.4. It is important that information within these stores is
consistent. If the information is inconsistent then you will find
that the metadata reported by different applications is
To try and reduce the amount of confusion caused by multiple
metadata entries, PDF 2.0 deprecated all Info entries apart from
the CreationDate and ModDate. To be PDF 2.0 compliant you should
put all metadata into the Metadata entry rather than the Info