In a recent video the Zettelkasten (which is a german word for creating a catalog of index cards) of Niklas Luhmann was explained in detail. https://www.youtube.com/watch?v=rUtCMdeqauE Somewhere in the Intenet there is a sophisticated Java software available which is mainly a relational database which has converted the idea into the digital age. But, both examples (the analog version and the software version as well) are not efficient enough. A more elaborated version of creating a Luhmann like Zettelkasten is explained next.
The idea is to a use a text file in an outliner tool like Scrivener or Lyx instead of using a database which provides different fields for date, keywords and references. The reason is, that database fields have to be filled and are not flexible enough. The main structure of a note taking app is based on keywords and keywords have much in common with sentences in a natural language.
Perhaps some explanations are helpful. New items are created in the add section. An item is equal to a paragraph and the title is shown in bold. Then some notes are enclosed also a reference is given. If the item was created in the add section it gets transferred into the main section into the correct category. This is done by simple copy&paste method of the outliner software.
Such a simplified pipeline is working closely with the original idea of a zettelkasten. The mechanism was known 300 years ago and it was not described by the index cards itself but by the workflow how to create new cards. What researchers and fiction authors have done in the past was the following.
1. They are going to the library and making notes into a normal book in a chronological order
2. At home, a scissors is taken to divide the page into sections
3. The sections (=items) are sorted by category into a card box
If the process is repeated frequently hundred of these cards are created. The card box is only the result the more interesting element is that scissor is needed to create the items from the written notes. In the screenshot this workflow can be emulated with an outliner tool much easier. New items are added only in the add section and the main section is the archive.