There are some things we all know we must never do; lines we just must not even think about crossing. And then, there are the many things that we don't even have to think about. We know they are okay,assume the existence of such distinctions. But what about the grey areas, the things that might be seen as all right under some circumstances and might incur great disapproval from another point of view? If you can't trust your own judgement about those, it is time you learned to!