But it stays confusing, because one file excists in many places and the only difference between them is the copyright years.
It is not just the file as such that copyright falls under, but the project as a whole. You can also remove all years, accept the first? No, you can never remove the years. It is one year for every read the file was published. Than you always use year-year. That is different, that is a range of years -- not removing years. This sometimes works, sometimes it does not if there was a gap in publication.
