The Signed tab is available only in the Digital Signature Properties dialog box. Selections made here determine what happens when the user applies a digital signature to the form.
This is the default.
Prevents further changes to the digitally signed form, according to the selection in the pop-up menu:
Prevents any changes to any form field.
Allows changes only to the form fields you select by clicking the Pick button and selecting check boxes for the fields that you want the user to be able to edit after signing.
Prevents changes in only the form fields you pick.
Activates a custom JavaScript when the user digitally signs the form. Use the Edit button to change or create a new JavaScript action.