it depends on you, which do you prefer. maybe you don't want they know who you are so you decide to send a fake document to hide your real identity. and I think this is good for you especially if you want to stay in the dark. but if you are serious with the business, then I guess you can send your real document so they can know that you are a real person. it's back to you again and what you want to do later when the project needs their participant to send their document.