Bollinger Bands with Filling - indicator MetaTrader 5

This is a version of Bollinger bands made as a filled area. But to avoid just making the usual Bollinger bands with some more colors, this version has a choice of calculating the standard deviation as a sample or as an uncorrected deviation. The explanation for that would be the...

from https://tradingrobots.net/bollinger-bands-with-filling-indicator-for-metatrader-5/