A complex data type that represents the actions that can
be performed in the PDF document without invalidating the signature.
The PDFSignaturePermissions value is a member of
the PDFSignatureVerificationInfo and PDFSignatureVerificationResult data
types.
These string values are valid:
All:
All modifications to the PDF document are allowed.
FormFields:
Only modifications to the form fields are allowed.
FormFieldsAndComments:
Only modifications to the form fields and comments are allowed.
None:
Modifications to the PDF document are not allowed.
