Identifying forecasting run in an Absence Management formula

It is a common requirement to apply different entitlement rules during forecasting,  in comparison to the entitlement rules that need to be applied during the actual absence calculations. This requires a method to identify whether a certain formula is being invoked by the forecasting process or not. Use the "TXN ID" or "TXN RSLT OPTN" system variables to identify whether the run is a forecasting run or not. These system elements are available only during forecasting and their values can be effectively used in this scenario.