Using a Zettelkasten is about optimizing a workflow of learning and producing knowledge. The products are texts, mostly. The categories we deem fit currently are the following:
* **Knowledge Management:** general information about what it means to work and learn efficiently.
* **Writing:** posts on the production of lasting knowledge, and about sharing it with others through your own texts.
* **Reading:** posts about the process of acquisition of new things and the organization of sources. site 
Good introduction by Bryan Kam page with a follow up. page . Consider Niklas Luhmann's Text about Communicating with Slip Boxes.
The core of this Personal Knowledge Management process revolves around two collections of notes: Reference Notes which summarise source material and include a link to the source, and the collection of Evergreen Notes which are written in the interpretive part of the process.
The 20th-century German sociologist Niklas Luhmann managed to publish 70 books. He credits much of his success to his Zettelkasten, or "slip box."
_Luhmann, N. (1992). Communicating with Slip Boxes. In A. Kieserling (Ed.), & M. Kuehn (Trans.), Universität als Milieu: Kleine Schriften (pp. 53–61). page _