How Do the Interactive Features Work? DVD-Video players (and software DVD-Video navigators) support a com- mand set that provides rudimentary interactivity. The main feature is menus, which are present on almost all discs to allow content selection and feature control. Each menu has a still or motion background and up to 36 high- lightable, rectangular buttons (only 12 if widescreen, letterbox, and pan and scan modes are used). Remote control units have up/down and left/right arrow keys for selecting onscreen buttons, along with numeric keys, a select key, a menu key, a top menu (title) key, and a return key. Additional remote functions may include freeze, step, slow, fast, scan, next, previous, audio select, subtitle select, camera angle select, play mode select, search to program, search to part of title (chapter), search to time, and search to camera angle. Any of these features can be disabled by the producer of the disc, an act which is called user operation control (UOP). It’s commonly used to lock you into the copyright warning or movie previews at the begin- ning of the disc, or to keep you from changing audio or subtitle tracks dur- ing the movie.