This class represents the user property dictionary. This is definitively detailed in:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 329, page 569.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 362, page 736.

A user property dictionary defines a single named property attached to a structure element, allowing applications to associate custom metadata with logical document structures.

The N entry holds the property name as a text string. The V entry holds the value, which may be any PDF object type. The F entry provides a formatted text string for display.

The H entry, when true, marks the property as hidden from user interfaces while preserving it in the document for use by the application that created it.

System.Object
    WebSupergoo.ABCpdf14.Elements.Element
       WebSupergoo.ABCpdf14.Elements.UserPropertyElement