Which shortcut is used to play the timeline in reverse?

The J key is the correct choice for playing the timeline in reverse in Avid Media Composer. This functionality is a part of the software's comprehensive keyboard shortcuts designed to streamline editing processes. Pressing the J key initiates playback in reverse, allowing editors to quickly review footage or navigate through the timeline backwards. This is particularly useful during the editing process where reviewing transitions or checking the timing of cuts in reverse can enhance overall editing efficiency.

The A key, L key, and Spacebar serve different functions within Avid Media Composer. The A key is typically associated with marks or trim operations, the L key plays the timeline forward, and the Spacebar is a general play/pause toggle. Understanding these distinct functions helps users efficiently utilize the software for various tasks.