Q. How can I add a notation to an Excel formula without cluttering my spreadsheet with a bunch of those red comment triangles?
A. There are two ways. You can add a conventional comment and then hide it and the red indicator. To do that, click on Insert , Comment and then add your notation inside the box that appears.
Then, to hide the comment and the indicator, click on Tools , then Options , next the View tab, and under the Comments section, check None (see screenshot below).
When you want to see them again, go back to Options , where you can click on either Comment indicator only or Comment & indicator .
Another way—and for many experienced Excel users this is their preference—is to add a comment inside a formula. There will be no sign of the comment in the cell; instead, it will appear in the formula box at the top of the screen when your cursor passes over the cell. To do that, add + N(“your comment”) to the end of the formula. For example, the formula adding A1 through A3 and reporting that it came from Stan looks like this:
=sum(A1:A3) + n(“I got this formula from Stan”)
And this is what it looks like in Excel: