Represents the "Title" entry of the document information dictionary object.

It is an optional entry defined as part of the PDF 1.1 specification. It was deprecated in PDF 2.0.

It contains a string representing a PDF string object.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 317, page 550.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 349, page 712.