<small><cite class='h-cite via'>ᔥ <span class='p-author h-card'>Manfred Kuehn</span> in Taking note: Luhmann's Zettelkasten (<time class='dt-published'>08/06/2021 00:16:23</time>)</cite></small>
Note the use of the edge highlighted taxonomy system used on these cards:
Similar to the so called high five indexing system I ran across recently.
https://www.flickr.com/photos/hawkexpress/albums/72157594200490122/
I remember also seeing this as an indexing system for index cards in 2007. https://www.flickr.com/photos/hawkexpress/sets/72157594200490122/
It's not too dissimilar a pattern from the early 20th century edge-notched cards which were used to make sorting collections easier. https://en.wikipedia.org/wiki/Edge-notched_card Of course doing this for a notebook isn't going to work as easily.
I keep my index cards in chronological order : the newest card comes at front of the card box. All cards are clasified into four kinds and tagged according to the contents. The sequence is equivalent to my cultural genetic code. Although it may look chaotic at the beginning, it will become more regulated soon. Don't be afraid to sweep out your mind and capture them all. Make visible what is going on in your brain. Look for a pattern behind our life.
Example of a edge-based taxonomy system for index cards.
I've used something like this in a textbook before while also using different colored pens to help differentiate a larger taxonomy. I found it to be better for a smaller custom cpb that only had a narrow section of topics. In my larger, multi-volume commonplace, I have a separate volume that serves as an index and uses a method similar to John Locke's, though larger in scope and shape. Sadly in this case, the index would be much too large (with too many entries) to make the high five method practicable.