Beware of Editing the Form Definition!
The form definition is found under a form's workflow. There are two options to view and edit it: without action, and with action.
With action shows all the submit code and on-user action code. Without action just shows the underlying form fields.
I just discovered that if you edit a form definition's "without action" part and save, ALL the SUBMIT/DELETE code is deleted. There is no warning about this effect nor an option to revert to a saved version. Unfortunately, this has set me back a few hours to re-code two form almost from scratch.
Disappointed,
John Whitney