Represents the "RV" entry of the field dictionary object.

It is an optional entry defined as part of the PDF 1.5 specification.

This property may contain one of two different types:.

1) A string representing a PDF string object.

2) A TextStreamElement.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 220, page 432.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 226, page 527.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 222, page 434.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 228, page 529.

The rich value holds the field's content as an XHTML text string supporting inline formatting. Viewers that support rich text rendering use RV for display and V as the plain-text fallback.