Mike - I simply put "protection of my person and property", which worked for me. I took the advice of my trainer, Dave Johnson, who said it was best to keep it simple and direct. I think many others here on the forum have done the same. This establishes your legal right without going into alot of detail which may be misconstrued if the person reading it decides to second guess your reasons. I haven't heard of challenges to this simple statement. Also, I took my training course first, which helped with dozens of questions like this. Good luck!