Disable Comp name in Win2kPro?

How do you Disable Computer name when sending a message in Win2kPro using Net Send? I know there is a way to do it, but I can’t find it in any of the tech books I have. Of course I could be looking in the wrong area. I know how to stop receiving messages by turning off the Messenger Service, but how do I stop my computer name from being broadcast when I send a message?