The information neatly typed on the cards – which library workers sometimes supplemented with handwritten notes on front and back – includes details that in many cases are not typically part of the electronic catalog system, Virgo, that the University Library switched to in 1989. At the time, the catalog was transferred by scanning that captured only the front of the cards.
Libraries may have handwritten notes on the back of library card catalog cards in the 20th century, a practice which caused data loss in the case of the Alderman Library which only scanned the front of their cards in 1989 when they made the switch from physical cards to a digital catalog.