The "FYI- I'm a Spy!" Letter can sometimes be usefull to save you own skin by making someone else to become a jackass. It's one of the only items you can use while you are disguised. If you pin the letter on someone elses side or back, he suddently appeared to be an enemy-spy for his own team. He also get's to 50%-70% vulnerable against friendly fire without knowing it. But there are several ways to get rid of the letter: You can endure it for ten seconds, but you also can go underwater or being jarated. There are also ways to get rid of it when you visit the spawn cubboard or if you got airblasted. The letter is always available after the old letter is destroyed. The negative side for this weapon is, that you have to give up your sapping tool. And of course, you have to deside sometimes if you really want to kill him or to turn him into a jackass. You get the killing points if this enemy dies by friendly fire, and the killer himself gets the assist for it.