Welcome to an exciting new world of radio scanning! Recognizing that contemporary scanning receivers are too hard to program and use, GRE's engineers conducted extensive research to determine the functional require- ments for an entirely new scanning receiver user interface. We call this new user interface the Object Oriented User Interface (OOUI), and it is based on the premise that, to a hobbyist, a scanner is easiest to use if all of the things that can be scanned are handled using common conventions for interaction between the user and the radio, at least to the extent that this is possible given that the ”things” that can be scanned are different from one another in either subtle or major ways.