We have received many questions from users 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. To add a superscript¹, hold the Alt key and type 0185. Superscript² is Alt 0178 and superscript³ is Alt 0179. To use more special characters, see the Character Map program in Windows Accessories.