This is a mt4 version of Deviation scaled ma from Mladen's mt5 version and his description

Deviation scaled moving average was described in the “The Deviation-Scaled Moving Average.” article of July 2018 TASC
Since it is actually a sort of EMA (Exponential Moving Average made adaptive using what Ehlers calls "deviation scaling")

Deviation-Scaling is a technique for data smoothing that uses a dynamic smoothing coefficient. This coefficient is updated automatically in response to the size of price "fluctuations". In this method, the Standard Deviation from the mean serves as the metric for determining this size. Consequently, the result offers significant data smoothing, even in instances of minor price changes, while also rapidly adjusting to these variations.