This class represents the link annotation. This is definitively detailed in:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 173, page 394.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 176, page 479.

This class is always an indirect object because it inherits from AnnotationElement which is always an indirect object.

System.Object
    WebSupergoo.ABCpdf14.Elements.Element
       WebSupergoo.ABCpdf14.Elements.AnnotationElement
          WebSupergoo.ABCpdf14.Elements.LinkAnnotationElement

A link annotation activates a destination or action when the user interacts with the region it covers. It is the primary mechanism for clickable hyperlinks and cross-references in PDF.

Either the A or the Dest entry must be present, but not both. The QuadPoints entry refines the active region beyond the rectangular Rect, allowing a link to track non-rectangular text runs.

The H entry selects the visual feedback shown while the link is being activated: invert, outline, push, or none.