6aEts‖Opens the Chart Wall dialog, where you can modify the properties of the chart wall. The chart wall is the "vertical" background behind the data area of the chart.
To access this command...
Choose Format - Chart Wall - Chart dialog (Charts)
2gUm9‖Set the formatting options for the selected line or the line that you want to draw. You can also add arrowheads to a line, or change chart symbols.