This class represents the signature field time stamp dictionary. This is definitively detailed in:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 234, page 447.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 237, page 542.

System.Object
    WebSupergoo.ABCpdf14.Elements.Element
       WebSupergoo.ABCpdf14.Elements.SignatureFieldTimeStampElement

A signature field time stamp dictionary supplies the URL of a time-stamping authority for use when the field is signed. The Ff entry uses a flag bit to indicate whether use of this TSA is mandatory.