WF. Price Data
This is the data used to walk forward a system. If the field is blank, the bars used in 'Opt price data' will be used. This is a new function, and the likely best clues are 29, 30 , 31 for a 30 minute system. GSB will give you the average metrics of these three bars, and the code with performance metrics of each time frame.
Experimentation with best bar intervals to use is a good area of research advanced users.