The additional actions of a form field: keystroke, format, validate and calculate scripts.
public sealed class PdfFieldAdditionalActions : PdfAdditionalActions
ISO 32000-2 §12.6.3, Table 199 (PDF 1.3). Not defined for button fields.
kind:method, kind:property, kind:ctor. Press Esc to clear.CalculateGets the action that recalculates the field's value when another field changes (C), in the order of the form's CO.FormatGets the action before the field's value is formatted for display (F).KeystrokeGets the action when the user changes a character or a list selection (K).ValidateGets the action when the field's value changes, to validate it (V).