Represents the "Tabs" entry of the page object object.

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

It contains a string representing a PDF name object.

This item may take one of the following valid values:.

• R
• C
• S
• A
• W

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 30, page 79.

Adobe Supplement to the ISO 32000, BaseVersion: 1.7, ExtensionLevel: 3; Table: 3.27, page 23.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 31, page 106.