The notation BB(20,2) in short stands for BB(20SMA,2SD).
BB25 stands for 25 SMA ,which is flatter than 20 SMA.
In order to ,compensate for this flatness ,I increased the multiple before SD in one of my
threads.I used a parameter BB(24,2.4) here, which stands for 24 SMA and
2.4*SD .