The libraries using colored book cards to denote the classes are:
- East Orange Public Library.
- New York Public Library.
- St. Louis Mercantile Library—colors simply indicating fiction or non-fiction.
Those using colored book cards for their double file (borrower's and book) are:
- Boston Athenaeum.
- Oberlin College.
At the time of book's issue bookcards are dropped into a drawer through slots designating classes of the books issued by the following libraries:
- Carnegie Library of Atlanta.
- New York Public Library.
- Pratt Institute Free Library—designates
- fiction, non-fiction and
- teachers.
Libraries using temporary bookcards, filled out at time of book's issue by borrower or assistant:
- Iowa State.
- Tulane University.
- Virginia State.
- Wesleyan University.
Libraries using a borrower's record for privileged classes (professors, etc.) and a time record for students:
- Kansas University.
- Oberlin University.
- Syracuse University.
- Wesleyan University.