Represents the "Marked" entry of the mark information dictionary object.

It is an optional entry defined as part of the PDF 1.0 specification.

It contains a bool representing a PDF boolean object.

The PDF specification states that this item assumes a value of false if no value has been provided.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 321, page 556.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 353, page 719.