For developers, navigating through the default TDL and identifying the fields that used in the target report is difficult. Hence, the On-screen tooltip feature used to identify the Field or Report Names by placing the mouse pointer wherever required.
This behaviour works only in Developer Mode where the Tally application starts with a Command Line Parameter/DevMode.
The Field Name displays as a Tooltip, when the cursor points on the desired field within the Report.
In developer mode, you can see that the Report Name displays as a Tooltip, when the cursor not pointed on any of the fields within the Report.