IF COMMUNICATION CANNOT FAIL, IT STILL MOST USUALLY FAILS

Even if you pay great attention to make your communication unambiguous, effective, and understandable, there will still be too many risks you haven't taken care of. Moreover, your measures are at best functional most of the time, which means that the combined probability for your communication to fail in at least one of the ways in which it could fail is higher than you dare to imagine.

1.3 IF COMMUNICATION SEEMS TO SUCCEED IN THE INTENDED WAY, THERE'S A MISUNDERSTANDING

When communication seems to be simple, easy and successful, it's probably a total failure. The recipient looks happy and thankful, because he understood your message his way, which is what he likes, and very different from what you were actually saying.

An old Usenet saying tells us that to every complex question, there is an answer which is simple, understandable, and pleasant, and plain wrong. People love to accept simple answers; only later do they realize they were wrong. More harmfully, many wrong answers have the nasty feature of "working" at first sight. It's much more harmful to get such an answer than to get an answer which turns out to be bogus the first time you try it.

1.4 IF YOU ARE CONTENT WITH YOUR MESSAGE, COMMUNICATION CERTAINLY FAILS

Being content with the formulation of your message is a sure sign of having formulated it for yourself.