Cue marks are time-based points of interest with annotations.
            They function as high-level keyframe controls that let you associate
            a keyframe with a mark. Instead of viewing a clip over and over
            again in order to evaluate and record (usually on paper) important
            timing points, you can view footage and add cue marks. 
         
         Once you've set a cue
            mark, you can go back to the animation timeline and tweak the positions
            of the cue marks, give them names, and even add notes to them.
         
         You can also set keyframes
            based on these marks by navigating from one mark to another using
            the Next Cue Mark and Previous Cue Mark buttons.
         
         Setting keys links the
            temporal position of the keyframe to the cue mark at that time;
            as you move the cue marks, the keyframes follow. If you move a keyframe
            in time, the link to the cue mark is broken. However, by moving
            a keyframe to the exact time of a cue mark, you link the keyframe
            to that cue mark.
         
         To add a cue mark:
         
         
            - Select the Set Cue Mark button in the
               Player controls.
            
NoteYou can also set
               a cue mark by pressing the U key
               while your cursor is in an Animation Editor, or in the Player navigation
               bar's current frame counter. 
            
         To set a cue mark to a specific frame
            of a film clip:
         
         
            - Do one of the following:
               
                  - Drag the time cursor in the Player navigation
                     bar (or type in the frame number) to the frame on which you want
                     to set a cue mark.
                  
- Play the composition, so that you can
                     add cue marks during playback.
                  
 
- Select the Set Cue Mark button in the
               Player navigation controls (left side) or set the cue mark while
               the footage is playing by pressing the U key.
               Play-and-set is a more interactive method of adding cue marks.
            
- Repeat steps 1 and 2 to add more cue
               marks.
            
NoteYou can also add
               a cue mark by right-clicking in any Animation Editor and selecting
               Add at Select Time or Add From Current Time from the Cue Marks sub-menu. 
            
         To delete a cue mark:
         
         
            - Select the Cue Marks tab in the tool
               UI.
            
- Select a cue mark.
            
- Right-click and select Delete.
            
To delete a cue mark using the contextual
            menu in any Animation Editor:
         
         
            - Select the cue mark you want to delete
               by selecting the top of it (it will turn from black to yellow when
               selected).
            
- Right-click and select Delete (or Delete
               All) from the Cue Marks sub-menu.