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

It is defined as part of the PDF 1.2 specification.

It contains a string representing a PDF name object.

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 state selects one key in the AP entry's sub-dictionary. For widget annotations the state name matches the on-state name of the field so the widget's appearance reflects the current field value.