Chavigny, Paul Marie Victor. Organisation Du Travail Intellectuel, Recettes Pratiques à l’usage Des Étudiants de Toutes Les Facultés et de Tous Les Travailleurs. Paris: Delagrave, 1918. https://catalog.hathitrust.org/Record/011209555

Here Blair quotes Chavigny and Heyde, but crucially leaves out Bernheim, Langlois & Seignobos, and Beatrice Webb.

Check the others, specifically for index card references, but Webb uses slips or sheets (and often larger ones).

A manual on note taking practice that Blair quotes along with Paul Chavigny as being influential in the early 21st century.

The court file number is used to identify a document and goes back to the file regulations (AktO) of November 28, 1934 and its predecessors.

The German "file number" (aktenzeichen) is a unique identification of a file, commonly used in their court system and predecessors as well as file numbers in public administration since at least 1934.

Niklas Luhmann studied law at the University of Freiburg from 1946 to 1949, when he obtained a law degree, before beginning a career in Lüneburg's public administration where he stayed in civil service until 1962. Given this fact, it's very likely that Luhmann had in-depth experience with these sorts of file numbers as location identifiers for files and documents.

We know these numbering methods in public administration date back to as early as Vienna, Austria in the 1770s.

The missing piece now is who/where did Luhmann learn his note taking and excerpting practice from? Alberto Cevolini argues that Niklas Luhmann was unaware of the prior tradition of excerpting, though note taking on index cards or slips had been commonplace in academic circles for quite some time and would have been reasonably commonplace during his student years.

Are there handbooks, guides, or manuals in the early 1900's that detail these sorts of note taking practices?

Perhaps something along the lines of Antonin Sertillanges’ book The Intellectual Life (1921) or Paul Chavigny's Organisation du travail intellectuel: recettes pratiques à l’usage des étudiants de toutes les facultés et de tous les travailleurs (in French) (Delagrave, 1918)?

Further recall that Bruno Winck has linked some of the note taking using index cards to legal studies to Roland Claude's 1961 text:

I checked Chavigny’s book on the BNF site. He insists on the use of index cards (‘fiches’), how to index them, one idea per card but not how to connect between the cards and allow navigation between them.

Mind that it’s written in 1919, in Strasbourg (my hometown) just one year after it returned to France. So between students who used this book and Luhmann in Freiburg it’s not far away. My mother taught me how to use cards for my studies back in 1977, I still have the book where she learn the method, as Law student in Strasbourg “Comment se documenter”, by Roland Claude, 1961. Page 25 describes a way to build secondary index to receive all cards relatives to a topic by their number. Still Luhmann system seems easier to maintain but very near.

<small><cite class='h-cite via'>ᔥ <span class='p-author h-card'> Scott P. Scheper </span> in Scott P. Scheper on Twitter: "The origins of the Zettelkasten's numeric-alpha card addresses seem to derive from Niklas Luhmann's early work as a legal clerk. The filing scheme used is called "Aktenzeichen" - See https://t.co/4mQklgSG5u. cc @ChrisAldrich" / Twitter (<time class='dt-published'>06/28/2022 11:29:18</time>)</cite></small>

Link to: - https://hypothes.is/a/Jlnn3IfSEey_-3uboxHsOA - https://hypothes.is/a/4jtT0FqsEeyXFzP-AuDIAA

I keep seeing references to Paul Chavigny. Need to get my hands on a copy.

—Bruno Winck

Reminder to look up Roland Claude. I couldn't find his work in the usual spaces in English or French.

Paul Chavigny, Organisation du travail intellectuel: Recettes pratiques a` l’usage des e ́tudiants de toutes les faculte ́s et de tous les travailleurs (Paris, 1920)

Chavigny was an advocate for the index card in note taking in imitation of "accountants of the modern school". We know that the rise of the index card was hastened by the innovation of Melvil Dewey's company using index cards as part of their internal accounting system, which they actively exported to other companies as a product.

[[Antonin Sertillanges]]' book ''The Intellectual Life'' is published in 1918 in which he outlines in chapter 7 the broad strokes a version of the zettelkasten method, though writing in French he doesn't use the German name or give the method a specific name.<ref>{{cite book |last1=Antonin |first1=Sertillanges |author-link1= Antonin_Sertillanges |title=The Intellectual Life: Its Sprit, Conditions, Methods |date=1960 |publisher=The Newman Press |location=Westminster, Maryland |translator-last1= Ryan |translator-first1= Mary |translator-link1= |pages=186-198 |edition=fifth printing |language=English}}</ref> The book was published in French, Italian, and English in more than 50 editions over the span of 40 years. In it, Sertillanges recommends taking notes on slips of "strong paper of a uniform size" either self made with a paper cutter or by "special firms that will spare you the trouble, providing slips of every size and color as well as the necessary boxes and accessories." He also recommends a "certain number of tagged slips, guide-cards, so as to number each category visibly after having numbered each slip, in the corner or in the middle." He goes on to suggest creating a catalog or index of subjects with division and subdivisions and recommends the "very ingenious system", the decimal system, for organizing one's research. For the details of this refers the reader to ''Organization of intellectual work: practical recipes for use by students of all faculties and workers'' by {{interlanguage link|Paul Chavigny|fr}}<ref>{{cite book |last1=Chavigny |first1=Paul |title=Organisation du travail intellectuel: recettes pratiques à l'usage des étudiants de toutes les facultés et de tous les travailleurs |date=1918 |publisher=Delagrave |language=French}}</ref>. Sertillanges recommends against the previous patterns seen with commonplace books where one does note taking in books or on slips of paper which might be pasted into books as they don't "easily allow classification" or "readily lend themselves to use at the moment of writing."

Antonin Sertillanges recommends his reader to use a decimal system for organizing their slip box system based on that in L'Organisation du Travail intellectuel, by Dr. Paul Chavigny, Fellow of the Val de Grace, Delagrave, 1918.