@Kanefire, this is library (Library feature just came with Pine version 5). using this library in your scripts you can get the info if the current bar is in last Nth bar. for example real-time bar number is 20000 and you want your script to start running on the bar 19900 (last 100 bar) then you can include this library and call the function as canwestart(your_UTC, 100), 100 means last 100. so, these libraries are useful if you are a Pine programmer :)