The Better Bollinger Bands is a modification of the Bollinger Bands created by Dennis McNicholl, published in an article in October 1998.
This version for Prorealtime is an adaptation of the code that appeared on the Tradingview platform
REM BETTER BOLLINGUER BANDS
//del código de Better Bollinguer Bands de la plataforma Tradingview
//publicado por LazyBear
//adaptación para la plataforma Prorealtime
Ib=20
de=2
alp=2/(Ib+1)
src=(high+low+close)/3
if barindex>Ib then
mt=alp*src+(1-alp)*mt[1]
ut=alp*mt+(1-alp)*ut[1]
dt=((2-alp)*mt-ut)/(1-alp)
mt2=alp*abs(src-dt)+(1-alp)*mt2[1]
ut2=alp*mt2+(1-alp)*ut2[1]
dt2=((2-alp)*mt2-ut2)/(1-alp)
but=dt+de*dt2
blt=dt-de*dt2
endif
RETURN but as "BSup", dt as "centro",blt as "Binf"