At our library, each card can have five books on hold at once. The limit used to be ten, but last May (2009) the libraries in the area all changed this. All the libraries in the Treasure Valley are part of the hold system, so each patron has access to a much larger system. I can go online, log in to the library, and search for every book available in the system. (For some reason, the system is also linked to Twin Falls Library, but that is a tease. I am not allowed to put those books on hold.) Interlibrary loan is available through a different process.
When the book limit for holds dropped down to five books, I promptly helped my oldest child get a library card. This soon proved to be inadequate for our library needs, and my second child has also received a library card. Its working great. The kids do have books on hold, but most of the selections are for me. No one has questioned why my eight year old is checking out books that are clearly for more advanced readers.
Here's where it gets tricky. The library puts the hold books on a special shelf when they come in. They put the first four letters of the last name and the last four numbers of the library card on a slip of paper in the book. The hold books are then shelved alphabetically by last name. No big deal, right? Each member of my family has their own card number, and pretty soon I knew which was which. But then...my husband got a card at our new branch. The last four numbers that the library uses to differentiate each person are the same as our oldest child's last four numbers. Its statistically improbable that this would occur, but we beat the odds. When I pick up the books on hold, I have to know which card each book belongs to. Not that hard really, because the library won't even let you check out a hold book on a different card.
Two of the librarians, however, have taken issue with the duplicate card numbers. They appear flustered and distressed every time I check out with books from the two cards. They say we must come in and get the problem fixed. Why are they so upset? We have it figured out. Its under control. The other librarians seem okay with it. It just doesn't seem like that big of a deal to us.
We have books to pick up at the library. I hope we get the right librarian.