This class represents the permissions dictionary. This is definitively detailed in:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 258, page 477.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 263, page 589.

System.Object
    WebSupergoo.ABCpdf14.Elements.Element
       WebSupergoo.ABCpdf14.Elements.PermissionsElement

A permissions dictionary records the certification and usage-rights signatures governing what operations may be performed on the document. Only one certification signature (DocMDP) may be present. UR3 references a current usage rights signature; UR references the deprecated equivalent.