A display of the SMPTE timecode numbers, usually corresponding to each frame of picture viewed on a monitor. These numbers appear in a window that replaces a portion of the program image, usually at the bottom right of the screen. Depending on the equipment used, the timecode data in the window can be either generated in real-time from the source of the SMPTE timecode data, or have been recorded as a permanent part of the picture on a particular copy of a pre-recorded program. BITC is generally recorded onto copies of footage that will be used for off-line editing. The source of the SMPTE timecode data in this latter case is the sync track or control track of the original video footage.