I was having a conversation with my supervisor yesterday. He mentioned something about patent memo. Something that you can write your idea down, date it, have some witnesses to sign it and put it away. In case some day you need to patent the idea but someone else wants to patent the same idea. So that you can present the patent memo to prove that you have the idea first.
I tried to Google it, but nothing came up. Can anyone confirm such thing exists and is valid?