If you have hidden fields on a report, we recommend that you mark them so that they are easy to identify. Additionally, you may want to move hidden fields to a different location in the layout to avoid problems with formatting.
To add and identify a hidden field
In the development environment, on the Tools menu, choose Object Designer.
In Object Designer, choose Report, select the report to which you want to add a hidden field, and then choose the Design button.
On the View menu, choose Layout.
In Visual Studio Report Designer, on the View menu, choose Toolbox.
From the Toolbox, under Report Items, drag a Text Box to the report layout.
Tip If the hidden text box is in a table data region, we recommend that you insert a new row in the table and add the hidden text box to this new row. In the Properties window of the row, under Layout, you can change the value of the Height property to a value that is large enough so that you can view the row when you are designing the report, but small enough that it will not cause formatting problems when you print the report, such as 0.2cm. Select the text box that you created. On the View menu, choose Properties Window.
In the Properties window, under Font, set the Color property to Yellow, or select the yellow square from the drop-down list.
In the Properties window, under Position, expand Size, and then set the Width property to a small width, such as 0.15cm.
In the Properties window, under Visibility, set the Hidden property to True.
On the File menu, choose Save Report.rdlc.