The "library" in my school (sub 13 years old, the library was a few bookcases at best for a school of ~120 kids) had books from the central library in the town.

The "library" in my school (sub 13 years old, the library was a few bookcases at best for a school of ~120 kids) had books from the central library in the town. You could look up a book, reserve it and it would be delivered next week if available (no internet then, so it was a computer with the book list and reservation cards you had to fill in). If it was not available you would get a notice when it would arrive. Or you took your bike and drove the 5km but as a small kid that is not always an option and you'd have to get your parents to bring or help you get there. You could return all books there even if you picked them up elsewhere in the same library system. It's sort of a postal system I guess. It didn't get used too often, but it was a nice addition to the rotating book supply that was otherwise available. And it was also a nice learning experience for us small kids about how the libraries worked and we got to use computers.