See "Displaying Multiple Sets of Control Limits". The VREF=, VREFLABELS=, and VREFLABPOS= options are used to display and label the trial limits. You can also pass in the values of the trial limits ...

Example 4.8: Variable Length Holidays This example shows how you can mark vacation periods that last longer than one day on the Gantt chart. This can be done by using the HOLIDUR= option in the CHART ...