You can control whether a report item initially displays or is hidden when a user views a report. Also, by providing a plus or minus toggle on a text box, you can enable users to hide and display items interactively. This is called a drilldown action. For a table or matrix, you can show or hide static rows and columns, or rows and columns that are associated with groups. The main reason for hiding items is to provide a report that shows summary data but enables a user to drill down into detail data.