This is a note taking system using index cards. I’m copying this down because the original website and wiki for the PoIC system are gone and most other sites just refer to it with a now dead link.
How it works
Hawk describes four types of cards in his system:
The Record Card. He describes it as “a diary, note, account, health, weather, cook, any kind of records about us belongs to this class.” I’d say this is the incoming “stuff” of the day: appointments, notes to follow up on, etc.
The Discover Card. Hawk describes the Discover Card as “Things from my brain, mind, spirit, anything emerge from inside me, are classified into this class.” This is the result of a mind dump. Don’t worry about classifying when filling out a Discover Card. Just get whatever is on your mind out and onto paper.
The GTD Card. Here he combines the title of a project and several actions that pertain to it (here’s a look at the template in English). This reminds me of the “Hipstper PDA Template” I used religiously about 10 years ago.
The Cite Card captures other people’s ideas that warrant attention. He says, “Important here is distinguishing ‘your idea (Discovery Card)’ and ‘someone else’s idea (Cite Card).’ Source of the information must be included in the Cite Card. A book, for example, author, year, page(s) are recorded for later use.”
In essence this is a Commonplace book broken up into card sized chunks.
Speculation: You could probably make a digital version of this system much like Cyberzettel.com using Wordpress.