I'm find in my HD the indicator attached. I remember that i download it from this forum.
How i have to construe this indi?
RSTL is one of the indicators from a digital filters group. Maybe the good thing would be to read this thread (about 4 basic digital filters FATL, SATL, RFTL and RSTL) : https://www.mql5.com/en/forum/172934
PS; if you are referring to a possibility to change the calculating period of RSTL, RSTL does not have a thing like that. It is built with fixed weights for each and every price in the list of 99 prices that it is using to calculate each value