You put a comment in Excel and it puts a red triangle in the top right corner to indicate that there is a comment. But sometimes, it is necessary that comment should be visible when Excel is opened. This becomes very desirable feature when dealing with top executives. This is also a good feature to provide explanatory notes to your data.
This feature needs to be enabled Excel Options.
File > Options > Advanced > Under Display section, select Comments and Indicators
Now, whenever this Excel workbook is opened, the comments will be displayed always.
Note - After saving and closing your Excel workbook, you may like to restore this to Indicators only, and comments on hover again. Whosoever opens this workbook, the comments will always be visible to him. He need not change the setting to Comments and indicators.