There is some //'d code which I haven't finished working on, but it looks to be quite similar to , just using different math rather than standard deviations from the mean.
The bands itself is pretty self explanatory, price likes to use it as resistance when under it, it can trade inside it and it can use the upper as support when in a strong upward trend.
In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.