This indicator is designed to be used with Market Profile / Volume Profile trading techniques on a 30min chart.
The halfback of a candle is the mid point between the high and the low of the candle. A halfback trade can be taken once price retraces into this point as support/resistance using the prevailing trend as your trade direction.
One-Time-Framing is a fancy term for trending in one direction. One-Time-Framing happens when a candle breaks the previous candle's high without testing the low or when a candle breaks the low of the previous candle without testing the high. This indicates that the trend is one directional and opposing pressure is very weak. Taking trades in the opposing direction of multiple OTF bars is typically a bad trade setup.
Halfback and OTF setups are typically used on a 30min timeframe combined with Market or Volume Profile, but you can experiment with these setups on any timeframe if you wish.
I hope you all enjoy this indicator, comment below if you have any questions.