You do not set Down rules manually. BO Tester sets the Down rules automatically.
The Down rules work at the exactly same way as the Up rules, but the logical conditions are mirrored.
If you set an Up rule: “Momentum ruses”, the application will apply an opposite rule for Down - “Momentum falls”.
If the Up rule contains a Level, the program calculates the Level value for a Down position correspondingly. Let's have a RSI indicator with rule: “RSI crosses the Level upwards”, and the Level to be set to 30. BO Tester is clever enough to translate that rule to Down as follows: “RSI crosses the Level downwards” and will set the Level value for Down to be equal to 70.
Some indicators have equal rules for Up and for Down. For example, the ADX indicator determines the trend power, but it doesn't tell us whether there is a bullish or a bearish trend. In that case, the application applies equal rules in both directions. If you have “ADX rises” rule for UP, the program applies the same “ADX rises” for Down.
BO Tester also applies mirrored rules for the “band” indicators. For example, if you have a Bollinger Bands with a rule “The Bar opens above the Upper band” for Up, the Down rule will sound like: “The Bar opens below the Lower band”.