Thumbtack Code

An interesting tidbit of information came up during the discussion of a shooting over at Kim du Toit's place. Turns out the way to get Mormon's and Jehovah's Witnesses to leave you alone is this:

If you put a black or red thumbtack in your door frame they don’t knock.

Green means they're receptive to your message. Yellow means they aren't adverse to it. Red means the owner responded belligerently. Black means stay away. I'll have to remember this if I see people passing out Watchtower in my complex.