Represents the "AP" entry of the annotation dictionary object.

It is an optional entry defined as part of the PDF 1.2 specification.

It contains an AppearanceElement.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 164, page 383.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 166, page 465.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 252, page 467.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 255, page 565.

The appearance dictionary separates the annotation's visual representation from its logical definition. Conforming readers must use the appearance stream for rendering rather than reconstructing the appearance from annotation entries.