Represents the "NA" entry of the navigation node dictionary object.

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

It contains an ActionElement.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 163, page 380.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 165, page 461.

The next action is executed when the viewer moves forward through the navigation tree from this node. It can be any action type, enabling complex navigation behaviours.