Represents the "DPartRoot" entry of the catalog dictionary object.

It is an optional entry defined as part of the PDF 2.0 specification.

It contains a DocumentPartRootElement.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 28, page 73.

Adobe Supplement to the ISO 32000, BaseVersion: 1.7, ExtensionLevel: 3; Table: 3.25, page 23.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 29, page 101.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 242, page 458.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 245, page 555.

The DPartRoot entry references the root of the document part hierarchy, used in PDF 2.0 for documents composed of multiple logically distinct parts such as variable data printing jobs or multi-record documents.