You can add comments to the cells in the crosstab. The data source must have been refreshed before you add a comment. A comment is available internally as long as it is not explicitly deleted. For example, if you add a comment to a cell and then change the view on your data so that in the new navigation state the cell with the comment is not visible, it becomes visible again as soon as you change the navigation state so that the cell with the comment is visible.
You can either use the Analysis ribbon's Comments area to insert and manage comments, or right-click a cell and choose Insert Comment.
A red triangle in a cell indicates a comment. To view the comment, click the cell.