reply to u/TheVoroscope at https://www.reddit.com/r/antinet/comments/va2s09/comment/jtwqhd7/?utm_source=reddit&utm_medium=web2x&context=3

u/TheVoroscope, the only things I've seen on it are the original and what you've written. I suspect anything current will be quite niche and would require searching in the areas of academic journal articles or at the level of graduate studies within the library sciences where you might find something. Simon Winchester had a section on the rise and downfall of the Encyclopedia Britannica in his most recent book Knowing What We Know (2023) which has a brief mention of the Propædia, but it was broadly described as a $32 million dollar bomb that ended the Encyclopedia. I would suspect that the last printings in 2010 and 2012 were probably the last more as a result of the rise of internet usage than they were the form and function of the Propædia itself though.

https://thevoroscope.com/2022/06/27/sum-total-human-knowledge-4/

https://thevoroscope.com/2022/06/20/sum-total-human-knowledge-3/

While Heyde outlines using keywords/subject headings and dates on the bottom of cards with multiple copies using carbon paper, we're left with the question of where Luhmann pulled his particular non-topical ordering as well as his numbering scheme.

While it's highly likely that Luhmann would have been familiar with the German practice of Aktenzeichen ("file numbers") and may have gotten some interesting ideas about organization from the closing sections of the "Die Kartei" section 1.2 of the book, which discusses library organization and the Dewey Decimal system, we're still left with the bigger question of organization.

It's obvious that Luhmann didn't follow the heavy use of subject headings nor the advice about multiple copies of cards in various portions of an alphabetical index.

While the Dewey Decimal System set up described is indicative of some of the numbering practices, it doesn't get us the entirety of his numbering system and practice.

One need only take a look at the Inhalt (table of contents) of Heyde's book! The outline portion of the contents displays a very traditional branching tree structure of ideas. Further, the outline is very specifically and similarly numbered to that of Luhmann's zettelkasten. This structure and numbering system is highly suggestive of branching ideas where each branch builds on the ideas immediately above it or on the ideas at the next section above that level.

Just as one can add an infinite number of books into the Dewey Decimal system in a way that similar ideas are relatively close together to provide serendipity for both search and idea development, one can continue adding ideas to this branching structure so they're near their colleagues.

Thus it's highly possible that the confluence of descriptions with the book and the outline of the table of contents itself suggested a better method of note keeping to Luhmann. Doing this solves the issue of needing to create multiple copies of note cards as well as trying to find cards in various places throughout the overall collection, not to mention slimming down the collection immensely. Searching for and finding a place to put new cards ensures not only that one places one's ideas into a growing logical structure, but it also ensures that one doesn't duplicate information that may already exist within one's over-arching outline. From an indexing perspective, it also solves the problem of cross referencing information along the axes of the source author, source title, and a large variety of potential subject headings.

And of course if we add even a soupcon of domain expertise in systems theory to the mix...

While thinking about Aktenzeichen, keep in mind that it was used in German public administration since at least 1934, only a few years following Heyde's first edition, but would have been more heavily used by the late 1940's when Luhmann would have begun his law studies.

https://hypothes.is/a/CqGhGvchEey6heekrEJ9WA

When thinking about taking notes for creating output, one can follow one thought with another logically both within one's card index not only to write an actual paper, but the collection and development happens the same way one is filling in an invisible outline which builds itself over time.

Linking different ideas to other ideas separate from one chain of thought also provides the ability to create multiple of these invisible, but organically growing outlines.

https://archive.org/details/britannica_propaedia/mode/2up

The one-volume Propædia is the first of three parts of the 15th edition of Encyclopædia Britannica, the other two being the 12-volume Micropædia and the 17-volume Macropædia. The Propædia is intended as a topical organization of the Britannica's contents, complementary to the alphabetical organization of the other two parts. Introduced in 1974 with the 15th edition, the Propædia and Micropædia were intended to replace the Index of the 14th edition; however, after widespread criticism, the Britannica restored the Index as a two-volume set in 1985. ==The core of the Propædia is its Outline of Knowledge, which seeks to provide a logical framework for all human knowledge==; however, the Propædia also has several appendices listing the staff members, advisors and contributors to all three parts of the Britannica.

link to: - https://hypothes.is/a/ISNt8BBPEe2oTse1NiJv4w

The Outline of Knowledge appears in the Propædia volume of the Encyclopedia Britannica. It is similar to various olther classification systems like the Dewey Decimal system or the Universal Decimal Classification.