Global variables not only carry info from one piston to another, but they are used in multiple pistons. Why define the same thing many times if you only need define it once, and then let many pistons utilize it? My window groupings are like that, used in multiple pistons. I also have a Holiday variable that gets set based on the actions of one piston and used as a reference for action in two others… but by itself does not trigger anything. Presumably, that should also then be clear.
Additionally I have a Boolean week alternator variable (because the Webcore “once every two weeks” function does not work well) that gets set by one piston and called by another. But it is not a trigger. The day of the week is the trigger, and the piston only does its thing if the week alternator variable is true.
It would never have occurred to me to have the mere existence of a global variable be a trigger for actions. That’s not good programming practice… in fact, now that I have examined all my pistons I see that anything I have that defines a global variable is in its own piston, a piston designed specifically to set that variable. I’ve not even been consciously aware that’s what I was doing! Guess it’s a carryover from my days of actual programming (two decades ago lol)