You can insert comments in cells . The comments act like yellow sticky notes onscreen, except that the notes in Excel aren't in the way when you don't want to see them. The comments don't appear in the cell; when you insert a comment, Excel indicates that the comment resides within the cell by flagging the cell's upper-right corner with a red triangle. When you point to the cell , Excel displays the attached comment.
To attach a comment to a selected cell, select Insert, Comment or right-click over a cell and select Insert Comment. Excel opens the box shown in Figure 8.7. Type your comment in the box and press Enter. Excel automatically places your name at the beginning of the comment ( assuming that you entered your name when you installed Office). The name indicates who added the comment in case you work in a multiple- user environment. (You can erase the name if you don't want to see it.) You can leave co-workers notes if you edit worksheets as a team. You can also leave yourself a note to fill in data that you might get from an outside source later.
Figure 8.7. Comments help document the worksheet cells.
The section "Clearing Data" earlier in this hour tells you how to remove comments you no longer need.