I'm not disagreeing- in fact, I mentioned the inspector told me not to worry about it. I'm just curious- does anyone know what the actual rule is? I've never, ever, heard of anyone who could say they did. This is quite a ridulous thing to be able to say with a book thousands of pages long telling you these things, IMO. I mean given that how to figure it is covered in great detail in that book, they just don't bother telling you when you gotta use it.