This toolbar contains funtions that help to work with Markush structures and it is not visible by default.
To make it visible, choose View > Toolbars > Markush.
|  | Position Variation Bond | Creates a variable point of attachment to represent a connection point to a group of atoms. | 
|---|---|---|
|  | Frequency Variation | Creates a Repeating Unit with Repetition Ranges. | 
|  | R-group attachment | Adds an attachment to the structure. |