Slipped in between paragraphs about being worried that her family’s hiding place will be discovered by a new building owner and the fairness of rationing butter, Anne Frank mentions being gifted a zettelkasten to track her reading:
Father emptied a card file for Margot and me and filled it with index cards that are blank on one side. This is to become our reading file, in which Margot and I are supposed to note down the books we’ve read, the author and the date.
—Anne Frank (1929-1945), diary entry dated Saturday, February 27, 1943 (age 13)
Niklas Luhmann (December 8, 1927-1998), famous for his own 90,000+ slip reading file was a year and a half older than Anne Frank (June 12, 1929-1945) who received her first card index file in February 1943 (likely between the 27th, the date of her diary entry mentioning it and the prior diary entry on February 5th). It was given to her by her father at the age of 13. As would have been commonplace, she was intended to use it as a “reading file” to note down the books she’d read along with the author and the date.
One can only wonder at how many entries she would have made over the span of her life had it not come to such an abrupt end.
Frank, Anne. The Diary of a Young Girl: The Definitive Edition. Edited by Otto H. Frank and Mirjam Pressler. Translated by Susan Massotty. 1947. Reprint, New York: Bantam, 1997.