We have received several questions about how to add superscripts to chart labels that correspond to footnotes on the slide. Here's how you do it:
Click on the chart label you want to edit and move your cursor to the location where you want to insert the superscript. Right click on the label and choose the symbol icon from the floating menu. Select the superscript, subscript or other symbol to include in your label.
For more symbols, use the Character Map program in Windows Accessories. From Character Map, you can copy any symbol and then paste it into a label.