On the Qualitative Timeline chart correctness checking reports (CCRs) are displayed as vertical lines representing the frequency of the CCRs occurrence. The height of each line is constant.
You can turn the display of CCRs on/off through the context menu: for example, right-click the chart, go to the Events to show submenu and select Issues. The height of each CCR line depends on the level of the report. The lines representing errors are twice higher than the lines representing warnings.
The default event is Duration of Collective Operations.