In linear tape editing, what must inserts have?

In linear tape editing, inserts must have a control track because it contains the timing and control information essential for synchronizing playback and recording. The control track ensures that video and audio are played back in the correct sequence and align properly, allowing for accurate editing and insertion of new material.

While audio sync is important for aligning audio with video, the control track specifically governs the operation of the tape machine itself, which is crucial during editing. A visual overlay pertains to graphics or effects added to a video but is not essential for the basic function of inserts in linear editing. A backup tape is wise for safety reasons but not a requirement for executing edits themselves.