If you add a digital signature to a dynamic PDF form, you need to preserve the state of the form when it is signed. Preserving the form state ensures that scripting changes in a form are preserved when a form is saved. For example, if some fields are hidden when a form is signed, those fields should remain hidden when the form is saved and reopened.The form state can be preserved automatically or manually. If it is automatically preserved, scripting changes are automatically preserved when the form is saved. If it is manually preserved, scripting changes are preserved through scripting when the form is saved. Use the delta script object and the preSave and initialize events to manually preserve the form state. For more information about the delta object, see delta. For more information about the preSave and initialize events, see preSave event and initialize event.If the form is not certified, you can preserve the form state automatically or manually. If the form is certified, you must manually preserve the form state. Automatically preserving scripting changes and restoring the form state invalidates the digital signature in a certified form.