Represents the "T" entry of the hide action object.

It is a required entry defined as part of the PDF 1.0 specification.

This property may contain one of three different types:.

1) A string representing a PDF string object.

2) An array which contains Elements.

3) An AnnotationElement.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 210, page 426.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 214, page 518.