The public‑domain loophole is a classic puzzle. If the author died more than a hundred years ago the text itself is free, but the publisher’s edition can still be locked if they added new typesetting or commentary. I once found a 19th‑century play that was technically public domain, but the translator’s notes were still under copyright, so I had to choose whether to quote them or do my own rendering. It’s the kind of legal grey area that turns a dusty volume into either a treasure trove or a liability, depending on how you sort the fine print.