If not empty, this should be an expression that evaluates to a URL. After the report is generated, clicking on the field will cause the report viewer to navigate to the URL. The report viewer can be a web browser (for HTML reports), Adobe Acrobat (for PDF reports), or other viewer applications.
Not all report viewers support hyperlinks. The PrintPreview control that ships with .NET, for example, does not.
The field will be displayed as usual, based on the contents of its Text and Picture properties.
The LinkTarget expression is always evaluated, regardless of the setting of the Calculated property (which only applies to the display text). This allows you to bind the LinkTarget to a field in the data source, as show in the example below.