It def says to not sin the original, and it may be that you are supposed to mail copy you sign, but i think that all predates faxing the FFL and it is kind of a pointless regulation now. Just b/c it is pointless does not mean a bureaucrat is going to tell you to ignore it or that the rule book will change. Maybe you aren't allowed to fax 03s technically. I think I have only faxed them to set up accounts for distributors so I could see their pricing, so IDK.