Hugo Kornelis (10/28/2010)
I wrote that NULL does not represent unknown.
I understand that is what you wrote.
I thought maybe you would look at the referenced article before responding.
Let me grab another cut and paste of the BOL that was referenced for the question.
"The value NULL means the data value for the column is unknown or not available."
That is the very first sentance from the Books online:
http://msdn.microsoft.com/en-us/library/ms191270%28v=SQL.100%29.aspx
Now I understand that the Books Online have often been wrong.
Do you believe they are in this instance?