Represents the "DR" entry of the interactive form dictionary object.

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

It contains a ResourceElement.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 218, page 431.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 224, page 525.

The default resources dictionary is shared across all fields and used when auto-generating field appearances. It typically contains at minimum the fonts referenced by field DA strings.