Thanks Hugo. I'm glad to see that my practical use of NULL is the same as the ANSI standard.

Apparently, there are some bright minds out there who are in the Date camp and feel very strongly that NULL means unknown or any number of things. Even though, in reality, it is very well known that it simply means no data is present.

I can see why this creates confusion with concatenation. People in the "unknown" camp will have difficulty concatenating an unknown value with a known value. In contrast, it should be very easy to concatenate "no data present" with any known value. The result is simply the known value.