it is number of steps in progress ( its sum is 100% on progress bar during inst_finish. I do not like much design as it need manual report of steps. I much more prefer array with callbacks, but I do not design the API and it is used in many clients. Bad things is that it changed after any modification to this file and to be honest when I count it yesterday, I think some numbers are not correct, but it is not important as it is just some visual element.